God's Word often employs the metaphor of grafting a branch into a rootstock, the best known of which is Paul's use of it in Romans 11.
Paul describes physical Israel as broken branches, allowing gentile branches to be grafted in, ultimately leading to the return of Israel to God's grace.
Paul poses two questions in Romans 11: Has God discarded Israel for all time? Will God graft physical Israel into the Covenant people of Abraham?
Jeremiah compares studying and meditating upon God's Word to physical eating, enabling a person to receive spiritual energy, vitality, and health.