In the first month, from the fourteenth day of the month at evening, you shall eat unleavened bread until the twenty-first day of the month at evening.
Moses and Aaron here receive of the Lord what they were afterwards to deliver to the people concerning the ordinance of the passover, to which is prefixed an order for a new style to be observed in their months (Exo 12:1, Exo 12:2): This shall be to you the beginning of months.
Commenting on Exodus 12:1-20
In the first month,.... As it was now ordered to be reckoned, the month Abib or Nisan: the fourteenth day of the month at even, ye shall eat unleavened bread; that is, at the evening following, the fourteenth of Nisan, and which was the beginning of the fifteenth day, the Jews beginning their day from the evening: hence the Targum of Jonathan is,"on the fourteenth...
UNLEAVENED BREAD. (Exo. 12:15-51) Seven days shall ye eat unleavened bread, &c.--This was to commemorate another circumstance in the departure of the Israelites, who were urged to leave so hurriedly that their dough was unleavened (Exo 12:39), and they had to eat unleavened cakes (Deu 16:3).
Commenting on Exodus 12:15-51