Passover started at sundown on the fourteenth day of the first month, as the new day began (see study note on Leviticus 11:24–25). The Passover feast included a roast lamb, bitter salad greens, and bread without yeast (Exodus 12:8). These foods represented Israel’s freedom from Egyptian slavery.
The first month marked the start of the Jewish calendar as late as Ezra 6:19. The month’s earliest name was Abib (which means “spring, fresh grain”; Exodus 13:4; 23:15; 34:18; Deuteronomy 16:1). The name Nisan partly replaced Abib after the exile of Israel to Babylon (Nehemiah 2:1; Esther 3:7).