Originally, God's instructions stipulated that Passover was to be observed on Abib 14 in individual homes, with the blood of the lamb caught in a basin and smeared on the doorposts and lintel. However, during the reigns of zealous kings like Hezekiah and Josiah, reforms were instituted to bring Judah back to God's way, including observing Passover at the Temple rather than in homes, introducing a second way of keeping the festival. At the time of Jesus Christ, this resulted in two distinct Passover observances: one at the Temple, led by priests late in the afternoon of Abib 14, and another in homes at the beginning of Abib 14. Jesus and His disciples ate the Passover in a home, observing it as Abib 14 began, while the priests kept it as Abib 14 ended. Despite the limited space of the Temple and the short time slot for sacrifices, historical records indicate that far more lambs were slain by individuals at home than by priests at the Temple.

During the reigns of Hezekiah and Josiah, strong and righteous kings of Judah, the observance of Passover underwent significant changes from God's original commands. These Passovers, held at the Temple, marked a departure from the domestic sacrifices described in earlier scriptures. The kings personally supervised these Temple-centered Passovers to prevent a return to pagan practices, enforcing obedience due to the people's deep-rooted idolatry. Alongside the Passover lamb, numerous other sacrifices from flocks and herds, such as burnt, peace, and thank offerings, were made during the Days of Unleavened Bread, reflecting administrative decisions under unusual circumstances. Despite this deviation, God accepted these observances, though not as a replacement of His initial intent for a home-killed Passover. This acceptance stemmed from the hardness of heart among the people, making a Temple-centered celebration preferable to none at all under such extreme religious perversion. Historical accounts from the time of Christ indicate that many Jews still sacrificed the Passover lamb at home, adhering to God's original command for a domestic observance, while a smaller group, primarily religious leaders controlling the Temple, followed the pattern of Temple sacrifices. This resulted in two distinct Passover celebrations, highlighting a divergence in practice. The Temple sacrifices, often termed Passover offerings, included cattle and other animals not specified for the Passover lamb, which were offered during the Feast of Unleavened Bread, further distinguishing them from the original Passover command.

During the lifetime of Jesus Christ, the Jews observed Passover in two distinct ways. One was kept by the people in their homes in the evening as Abib 14 began. The other, led by the priests, was observed at the Temple in the late afternoon of Abib 14. While most people sacrificed lambs throughout the city as Abib 14 approached, the priests would not slay the Temple Passover lambs until the following afternoon.

The practice of sacrificing Passover lambs at the Temple emerged as a significant change influenced by historical figures like Hezekiah, Josiah, and Ezra, who centralized worship to control religious observances and prevent the people from straying from God's law. This shift moved the sacrifice from homes to the Temple, a change not originally commanded by God. Historical records, such as those from Josephus in "Wars of the Jews," describe the vast numbers of people participating in Passover at Jerusalem, highlighting the scale of Temple sacrifices during this period. Despite these large gatherings, the centralization represented a departure from the original instructions given in Exodus 12, Leviticus 23, and Numbers 9, which Jesus Christ adhered to by keeping Passover at the beginning of the 14th day, not following the later Temple-based tradition. The New Testament accounts, including John 13:1, clearly distinguish that Jesus observed Passover according to God's original command, not aligning with the Jewish practice of a Temple-sacrificed lamb on a different day. This adherence underscores that the authority to alter God's commandments was never granted to human leaders, regardless of their intentions.

Passover, as originally instituted, occurred at the beginning of the fourteenth day, with the lamb being killed at home and its blood sprinkled on the doorposts. The entire day was devoted to preparations, including slaying, cleaning, and roasting the lamb, staying in houses through the night of the Death Angel, burning the remains, and gathering for departure during the daylight portion of the fourteenth. God demands work on this day in preparation for the feast that follows, marking the memorial of coming out of sin at sunset of the fourteenth into the fifteenth. This domestic observance set the pattern for all Passovers until changes occurred. Later, a shift is noted where proponents of a fifteenth Passover claim that after the original domestic celebration, lambs were sacrificed at the tabernacle or temple, with blood sprinkled on the base of the brazen altar instead of doorposts. This change is questioned, as no clear command from God is found in His Book to transition from domestic to temple sacrifices for Passover. Even after the establishment of the tabernacle and priesthood, as detailed in Exodus and Numbers, God did not alter the original instructions for Passover, maintaining it as a domestic observance without a specified temple sacrifice or holy convocation. Historical accounts from scholars like Philo, a contemporary of the time of Jesus Christ, highlight that Passover was distinct from other sacrifices, uniquely observed outside the temple context. Contrasts between the original and traditional practices show significant differences: the original lamb was killed at the beginning of the fourteenth at home, eaten on the night of the fourteenth, with blood on doorposts, commemorating Passover over eight days including Unleavened Bread; the traditional practice involved killing the lamb at the end of the fourteenth at the temple, eating it on the night of the fifteenth, with blood on the altar, commemorating the Exodus over seven days incorrectly termed as Passover. These alterations reflect major changes in the observance and meaning of Passover and Unleavened Bread.

Under the reign of Hezekiah, a significant reform took place concerning the observance of Passover. Due to a period of extreme spiritual rebellion, Hezekiah took authoritative control, initiating a revival by commanding the cleansing of the Temple. Since the regular time for Passover had passed, he ordered its observance in the second month, along with the Days of Unleavened Bread, as permitted for those unclean at the first Passover. However, this was done at the king's command, not directly by God's instruction, marking an unusual circumstance. Hezekiah moved the Passover sacrifice from individual homes to the Temple, personally supervising to ensure it was not corrupted by pagan practices, reflecting his concern that without such oversight, the people might honor Baal instead of God. Similarly, during Josiah's reign, another national emergency arose after a period of deep paganism under Manasseh. Josiah, like Hezekiah, used the power of his office to enforce reforms, personally overseeing the Passover observance. He mandated that the sacrifices occur at the Temple rather than at individual homes, fearing the people would revert to pagan rituals if left unsupervised. This Passover included additional offerings beyond the traditional lamb, such as cattle for burnt, peace, and thank offerings, conducted over the Passover day and the Days of Unleavened Bread. For the first time, the entire eight-day period was referred to as Passover, a notable shift from earlier distinctions. In both instances under Hezekiah and Josiah, the kings assumed control during spiritual crises, altering the traditional domestic observance of Passover to a centralized Temple sacrifice. This was done to safeguard the integrity of the celebration amidst widespread pagan influences, ensuring at least a semblance of adherence to God's commands, even if not in the exact manner originally prescribed.

The Passover, as a significant observance, was to be sacrificed and eaten with specific instructions given by God. It is named for God passing over the houses of the children of Israel while they remained in their homes, as detailed in Exodus 12:13, where the blood on the houses served as a sign for God to pass over and spare them from the plague in Egypt. Exodus 12:25-27 further emphasizes that this service commemorates the Lord's Passover sacrifice, protecting the Israelite households during the striking of the Egyptians. The ordinance of the Passover, as outlined in Exodus 12:43-48, specifies that it must be eaten in one house, not carried outside, and no bones are to be broken. No outsider or uncircumcised person is to partake unless circumcised and integrated as a native of the land. The emphasis in these instructions is on the eating of the Passover, more so than the killing, indicating its importance in maintaining the observance. Historically, the practice of sacrificing the Passover at the Temple emerged among some Jews, contrary to the original command to slay it at the house, as recorded in Exodus 12. Josephus, in "Wars of the Jews," notes that high priests performed the sacrifices at the Temple from mid-afternoon, a deviation from the household setting. In "Antiquities of the Jews," he mentions that while some adhered to the traditional home observance, others followed the Temple practice, reflecting a dual observance during his time. This shift to Temple sacrifice influenced interpretations of the timing phrase "between the two evenings," with some Jewish scholars like Rashi and Kaplan defining it as mid-afternoon to sunset to accommodate Temple rituals. However, this interpretation conflicts with the original instructions preserved in Scripture, which indicate the Passover sacrifice and related rites occur at the beginning of the fourteenth day, aligning with the period following sunset, as clarified through biblical usage in Exodus 16. God never altered the command to sacrifice at the house, underscoring the importance of adhering to the original ordinances in observing the Passover.

The original instructions for Passover, as detailed in Exodus 12, emphasized a domestic observance where the lamb was killed at home by the head of the family at the beginning of the fourteenth day of the first month. In contrast, the later Jewish tradition shifted this practice significantly, mandating that the lamb be sacrificed at the temple by a priest at the end of the fourteenth day. This change altered the setting and authority of the ritual, moving it from a family-centered event to a centralized, priestly function. Furthermore, while the original command directed the blood to be sprinkled on the doorposts, the traditional practice saw the blood sprinkled on the altar with the fat burned there as well. These alterations, among others, reflect a major reinterpretation of the Passover observance, diverging from the initial divine instructions given to Israel.