Exodus 23:15 in the World English Bible
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.
Context
14 Three times thou shalt keep a feast unto me in the year.
15 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:)
16 And the feast of harvest, the firstfruits of thy labours, which thou hast sown in the field: and the feast of ingathering, which is in the end of the year, when thou hast gathered in thy labours out of the field.