Exodus 12:11

8 And they shall eat the flesh in that night, roast with fire, and unleavened bread; and with bitter herbs they shall eat it.

9 Eat not of it raw, nor sodden at all with water, but roast with fire; his head with his legs, and with the purtenance thereof.

10 And ye shall let nothing of it remain until the morning; and that which remaineth of it until the morning ye shall burn with fire.

11 And thus shall ye eat it; with your loins girded, your shoes on your feet, and your staff in your hand; and ye shall eat it in haste: it is the LORD'S passover.

12 For I will pass through the land of Egypt this night, and will smite all the firstborn in the land of Egypt, both man and beast; and against all the gods of Egypt I will execute judgment: I am the LORD.

13 And the blood shall be to you for a token upon the houses where ye are: and when I see the blood, I will pass over you, and the plague shall not be upon you to destroy you, when I smite the land of Egypt.

14 And this day shall be unto you for a memorial; and ye shall keep it a feast to the LORD throughout your generations; ye shall keep it a feast by an ordinance for ever.