Exodus 34:23-25

Revised Standard Version

²³ Three times in the year shall all your males appear before the Lord God, the God of Israel. ²⁴ For I will cast out nations before you, and enlarge your borders; neither shall any man desire your land, when you go up to appear before the Lord your God three times in the year.

²⁵ “You shall not offer the blood of my sacrifice with leaven; neither shall the sacrifice of the feast of the passover be left until the morning.