John Wesley on Deuteronomy 16:1

Observe the month of Abib - Or of new fruits, which answers to part of March and part of April, and was by a special order from God made the beginning of their year, in remembrance of their deliverance out of Egypt. By night - In the night Pharaoh was forced to give them leave to depart, and accordingly they made preparation for their departure, and in the morning they perfected the work.