God told the Hebrews when to observe the Passover and Feast of Unleavened Bread. At first, to be honest, the command seems random.
The feasts were to occur at the appointed time of Abib, or Aviv (Exodus 23:15)—a Hebrew word that refers to the time in spring when the grain begins to ripen. The first Passover occurred on the fifteenth day of Nisan, which became the first month of the Jewish calendar.
This timing occurred for good reason.
The Lord gave His people a plain explanation why the celebration should coincide with spring:
For [then] you came out of Egypt. —Exodus 23:15
God linked the Passover celebration with their redemption.
But why the springtime? There was a problem with the calendar that had to get fixed. Its fix offers a lasting lesson.
Even for Christians.