Exodus 23:15
15 qYou shall keep the Feast of Unleavened Bread. As I commanded you, you shall eat unleavened bread for seven days at the appointed time in the month of rAbib, for in it you came out of Egypt. sNone shall appear before me empty-handed.
Deuteronomy 16:16
16 b“Three times a year all your males shall appear before the Lord your God at the place that he will choose: at the Feast of Unleavened Bread, at the Feast of Weeks, and at the Feast of Booths. cThey shall not appear before the Lord empty-handed.