Exodus 13:10

13:10 So you must keep this ordinance at its appointed time from year to year.

Exodus 15:26

15:26 He said, “If you will diligently obey the Lord your God, and do what is right in his sight, and pay attention to his commandments, and keep all his statutes, then all the diseases that I brought on the Egyptians I will not bring on you, for I, the Lord, am your healer.”