If the Reader will calculate, he will find that the fourteenth day at even was the night of deliverance from Egypt. And the one and twentieth day perhaps was the day of their passage through the Red Sea. Exodus 14:29.
Related Commentaries of Exodus 12:18
Exodus 12:18
18 In the first month, on the fourteenth day of the month at even, ye shall eat unleavened bread, until the one and twentieth day of the month at even.