John Gill Commentary Leviticus 23:6

"And on the fifteenth day of the same month is the feast of unleavened bread unto Jehovah: seven days ye shall eat unleavened bread." — Leviticus 23:6 (ASV)

And on the fifteenth day of the same month [is] the feast of unleavened bread unto the Lord Which was the day the children of Israel went out of Egypt with their dough and leaven, having not time to leaven it; in remembrance of which this feast was appointed: seven days you must eat unleavened bread ; see (Exodus 12:15Exodus 12:18–20) .