Book Four of the Psalms, encompassing Psalms 90 through 106, with Psalm 149 as its summary, holds a significant place within the Psalter, though it comprises only 17 psalms, or 18 with the summary, representing a mere 11.3 to 12 percent of the total 150 psalms. This relatively small portion is dedicated to the fall season, a time of profound spiritual scope marked by the fall festivals, yet it seems limited in number for such an eternally significant period. Nevertheless, in His wisdom, God deemed these psalms sufficient to convey the essential messages of this season. Book Four aligns with the fall, paralleling the Book of Numbers in the Pentateuch and the Book of Ecclesiastes among the festival scrolls. Its themes resonate with the events and spiritual implications of the fall festivals, including the Feast of Trumpets, the Day of Atonement, the Feast of Tabernacles, and the Last Great Day, pointing to future events in God's plan such as the return of Christ, the unification of man with God, the Millennium, and eternity with Him. Several key themes emerge from Book Four. The first is numbering, reflecting the census in Numbers and the call in Psalm 90 to number our days to gain a heart of wisdom, urging a proper perspective on life's brevity and priorities. This theme also appears in Ecclesiastes, emphasizing the importance of remembering our Creator early in life to live purposefully under God's watch. The second theme is God's judgment, evident in Numbers through various judgments on Israel during their wilderness wanderings, and in Ecclesiastes through reminders of God's oversight and ultimate accountability. In Book Four, psalms such as 94, 96, 97, 98, and 106 highlight judgment, often linked with the return of Christ, underscoring the need to live in alignment with His will to receive a favorable judgment. Thirdly, God's sovereignty is a prominent theme, showing Him as in complete control, guiding His people despite their waywardness, as seen in Numbers and Ecclesiastes. Book Four frequently portrays God on His throne, ruling over all and directing everything according to His plan, reassuring that even amidst chaos, He remains sovereign. The fourth theme is the vast difference between God and man, illustrated in Numbers by man's sinfulness and weakness contrasted with God's purity and eternity, and echoed in Ecclesiastes with man's transient life under the sun versus God's overarching control. Psalms 90, 105, and 106 in Book Four emphasize this disparity, highlighting the need for a proper perspective to bridge the gulf between human imperfection and divine perfection. Finally, the theme of salvation emerges as central to Book Four, answering the question of how man can reach God's level. In Numbers, God repeatedly saves Israel, acting as their Redeemer. Ecclesiastes hints at His saving power, while Book Four's psalms portray Him as the Savior across various dimensions of salvation during the fall festival period, from the firstfruits to the whole world in the Millennium and beyond. Psalm 90, the keynote of Book Four, encapsulates these themes, beginning with the disparity between God's eternity and man's transience, pleading for mercy and wisdom to number our days rightly. It transitions from despair under judgment to hope for joy and God's presence, envisioning a future where His beauty and holiness transform His people. The psalm hinges on the plea for God to teach us to number our days, a cooperative process where He reveals and we respond through experience to gain a heart of wisdom, aligning with the ultimate goal of the fall festivals to prepare us for His Kingdom and eternal life with Him.

Book Four of the Psalms, encompassing eighteen psalms from Psalm 90 to Psalm 106, along with Psalm 149 as the Psalm, holds a significant place within the Psalter's structure, correlating with the fall season. This collection aligns with the book of Numbers, reflecting themes of wandering and divine guidance, and parallels the book of Ecclesiastes, which emphasizes a wise walk through life. Over a series of sermons spanning the fall holy days—Trumpets, Atonement, Feast of Tabernacles, and the Last Day of the Feast—focus will be placed on these psalms to explore their connection to the fall festivals and the prophetic fulfillments inherent in them. The themes of Book Four resonate deeply with the Day of Trumpets, highlighting the return of Christ, judgment, and the display of His wrath, alongside His protection and deliverance of His people amidst great destruction. Despite the chaos and devastation foretold, these psalms emphasize that He will be with His people, safeguarding them through tumultuous times toward a promised future. The perspectives of the psalmists, such as David and Moses, mirror our own as they anticipate future events, using varied tenses—past, present, and future—to convey timeless lessons applicable to this season. Specific psalms within Book Four, like Psalm 90, a prayer of Moses, seek wisdom to number our days and gain a heart aligned with His eternal perspective, yearning for the establishment of our work in His Kingdom. Psalm 91 further illustrates covenant loyalty and intimate knowledge of His character, promising deliverance, honor, and salvation to the faithful. Psalm 94 offers assurance of His sovereignty over evil, while Psalm 96 rejoices in His imminent coming. These psalms collectively weave a narrative of anticipation, judgment, protection, and ultimate praise for His enduring presence and plan.

Book Four of the Psalms reflects profound themes that resonate with the fall festival season of the Hebrew calendar. These themes emphasize the importance of numbering or counting, urging a deep consideration of how to prioritize life. They also highlight God's judgment, underscoring the necessity of prioritization as He watches and will judge according to deeds, promising to come and judge the nations righteously and justly. God's sovereignty stands paramount, as He rules over all, actively working out His plan to bring His people into His Kingdom, controlling events and soon establishing a Kingdom to rule everyone and everything. The vast disparity between God and man is evident, with Him as Creator, King, and Judge, while humanity is insignificant in comparison, yet granted access through Jesus Christ. Salvation emerges as a key theme, with God on a mission to redeem not just His people Israel or the church, but all mankind, desiring unity with all through frequent and awesome acts of deliverance and redemption. Psalm 149, the summary psalm of Book Four, encapsulates these themes, focusing on the saints and their role at the time of Christ's return. It portrays the joy and exaltation of God's saints as the Millennium begins, having been made like Christ and performing duties as the Bride of Christ, balancing raw jubilation in praise for God with a sense of responsibility for their new roles as kings and priests under Him. The phrase "Sing to the Lord a new song," appearing in Psalm 149 as well as in Psalms 96 and 98 within Book Four, identifies these saints as the redeemed, the firstfruits glorified at Christ's return. The psalm reflects the disparity between God and man, with Israel rejoicing in their Maker, and the saints as children of Zion under their King, from whom all power and authority flow. Salvation is evident as the Lord takes pleasure in His people, beautifying the humble with salvation, while the latter part of the psalm addresses judgment, with the saints executing vengeance and punishment, binding kings, and carrying out written judgment. These themes of Book Four, reiterated in Psalm 149, firmly place its relevance at the beginning of the Millennium, where the saints, glorified and married to Christ, undertake the responsibilities of that era under His guidance. This reflects the ultimate goal of God's plan, observed in the fall festivals, looking forward to a glorious time when His people are brought into His family.

Book Four of the Psalms, particularly through Psalm 104, presents a profound meditation on God as Creator, emphasizing His greatness and ongoing involvement in the world. This book aligns with the theme of the fall season, reflecting creation and new beginnings, which ties into the civil year's start on Tishri 1, the Day of Trumpets. Psalm 104, paired with Psalm 103, forms a thematic duo, both beginning and ending with "Bless the Lord, O my soul!" to underscore their shared focus on praising God for His works and benefits. Psalm 104 specifically focuses on God's creative acts, portraying not only what He has done but also what He continues to do, culminating in glory for Him and for us. It follows the creation account in Genesis 1 poetically, using metaphors and imagery to inspire awe, such as depicting God clothing Himself in light and commanding the waters to stay in their place. This psalm reveals God as intimately involved in His creation, sustaining it through His power and ensuring everything works together for a purpose. David's reflections in Psalm 104 highlight that all elements of creation, from vast oceans to small springs, cooperate intricately, demonstrating God's design for unity and purpose. He shows that God provides abundantly for mankind, offering not just sustenance but joy, health, and strength through His creation. Cycles of day and night, seasons, and animal behaviors are orchestrated for man's benefit, revealing God's thoughtful provision. Moreover, Psalm 104 emphasizes God's ongoing sustenance of nature, with creatures depending on Him for life and breath. It portrays His Spirit as a powerful force of creation and renewal, capable of transforming and glorifying. Yet, it also acknowledges God's power to destroy, reminding us to fear His justice alongside marveling at His wonders. David concludes with a longing for a time when sin is removed, envisioning a harmonious creation in alignment with God's ultimate purpose. Through these themes, Book Four, especially Psalm 104, calls us to worship and praise God for His unmatched greatness and purposeful design.

In the context of the broader discussion on human failure and divine redemption, Book Four of the Psalms, particularly Psalms 105 and 106, holds significant relevance. These two psalms, which conclude Book Four, are seen as teaching tools that reflect on God's historical dealings with Israel and project forward to the time of the Great White Throne Judgment, envisioning the general conversion of humanity. Psalm 105 recounts the journey of Israel from Abraham through their wanderings in the wilderness to the Promised Land, highlighting God's faithful provision and leadership through every challenge. It illustrates how He provided leadership, delivered them from Egypt through plagues, granted them wealth and health, and sustained them with food, water, and guidance in the desert. This psalm emphasizes that God fulfills His covenant promises, providing all that is necessary for His people as they journey toward His Kingdom, asking only that they follow His path. Psalm 106, in contrast, focuses on Israel's persistent disobedience and faithlessness, yet underscores God's enduring mercy and repeated deliverance. Despite their sins and provocations, including grave acts like sacrificing their children to demons, God continued to show mercy, often beyond what they deserved, always working toward the ultimate goal of salvation. This psalm reveals a pattern of temporary repentance followed by renewed failure, yet God's mercy persists, aiming to bring His people to salvation. Together, these psalms present a stark contrast between human failure and divine faithfulness. They serve as powerful lessons for those in the future resurrection, demonstrating that God can be trusted to act with unwavering faithfulness and mercy. They teach that, despite past misunderstandings or skewed perspectives of God's actions, He has always been just, gracious, and committed to His covenant, working tirelessly for the salvation of His people. Through these teachings, humanity will come to recognize God's sovereignty, goodness, and holiness, turning to Him with joy at the prospect of His salvation.

Book Four of the Psalms resonates deeply with the themes of the fall holy days, reflecting our profound neediness and God's boundless providence. While none of the psalms in this book are explicitly labeled for specific occasions like the Day of Atonement, the Feast of Trumpets, or the Feast of Tabernacles, their themes often align with these observances through the words and ideas expressed. Psalm 102 portrays a vivid picture of human affliction and divine response. It begins with a prayer of the afflicted, overwhelmed and pouring out complaints before the Lord, mirroring the state of ritual affliction experienced on the Day of Atonement. The psalmist describes a condition of dire straits, reminding us of our finite and frail nature, how quickly our days are consumed like smoke, and how our hearts wither like grass. This theme of human weakness recurs throughout Book Four, as seen in Psalm 90, where the psalmist contrasts God's immense strength with humanity's frailty, pleading for divine help to make something good of fleeting lives burdened by sin. In Psalm 102, the structure unfolds in three parts: the first third details the psalmist's affliction, the second highlights God's sovereign work, and the final third emphasizes God's eternity and changelessness. This progression offers solutions to affliction, applicable to every person under distress, revealing that true hope and betterment lie solely in what God can and has promised to do. The psalm pivots as the psalmist shifts focus from self to God, recognizing His mercy, power, and eternal character as the answer to despair. God's mercy is directed toward His people, symbolized by Zion, at an appointed time, pointing toward future acts of grace, including the atoning work associated with Christ's comings. Psalm 103 continues the tone of hope and joy from the end of Psalm 102, becoming a psalm of praise and thanksgiving. It extols God for His manifold benefits, emphasizing that everything good comes from Him. The psalm lists these benefits, starting with the forgiveness of iniquities through His atoning work, which restores the relationship between humanity and God, enabling further spiritual blessings. God's mercy and grace are highlighted as He removes sins completely, urging us to move forward. The psalm also notes that God's mercy extends to those who fear Him, keep His covenant, and follow His commandments, presenting these responses as a small price for His immense blessings. Ultimately, it calls all creation to praise God for His wonderful deeds and boundless goodness.