Joshua 5:10, 1 Corinthians 5:7
The children of Israel encamped in Gilgal. They kept the Passover on the fourteenth day of the month at evening in the plains of Jericho. Purge out the old yeast, that you may be a new lump, even as you are unleavened. For indeed Christ, our Passover, has been sacrificed in our place.