Exodus 23:15 in the King James Version
Thou shalt keep the feast of unleavened bread: (thou shalt eat unleavened bread seven days, as I commanded thee, in the time appointed of the month Abib; for in it thou camest out from Egypt: and none shall appear before me empty:)
Context
14 “You shall observe a feast to me three times a year.
15 You shall observe the feast of unleavened bread. Seven days you shall eat unleavened bread, as I commanded you, at the time appointed in the month Abib (for in it you came out of Egypt), and no one shall appear before me empty.
16 And the feast of harvest, the first fruits of your labors, which you sow in the field; and the feast of ingathering, at the end of the year, when you gather in your labors out of the field.