God said to Moses and Aaron while still in Egypt,
"This month is to be the first month of the year for you.
Address the whole community of Israel; tell them that on the tenth of this month each man is to take a lamb for his family, one lamb to a house.
If the family is too small for a lamb, then share it with a close neighbor, depending on the number of persons involved. Be mindful of how much each person will eat.
Your lamb must be a healthy male, one year old; you can select it from either the sheep or the goats.
Keep it penned until the fourteenth day of this month and then slaughter it - the entire community of Israel will do this - at dusk.
Then take some of the blood and smear it on the two doorposts and the lintel of the houses in which you will eat it.
You are to eat the meat, roasted in the fire, that night, along with bread, made without yeast, and bitter herbs.
Don't eat any of it raw or boiled in water; make sure it's roasted - the whole animal, head, legs, and innards.
Don't leave any of it until morning; if there are leftovers, burn them in the fire.
"And here is how you are to eat it: Be fully dressed with your sandals on and your stick in your hand. Eat in a hurry; it's the Passover to God.
"I will go through the land of Egypt on this night and strike down every firstborn in the land of Egypt, whether human or animal, and bring judgment on all the gods of Egypt. I am God.
The blood will serve as a sign on the houses where you live. When I see the blood I will pass over you - no disaster will touch you when I strike the land of Egypt.
"This will be a memorial day for you; you will celebrate it as a festival to God down through the generations, a fixed festival celebration to be observed always.
You will eat unraised bread (matzoth) for seven days: On the first day get rid of all yeast from your houses - anyone who eats anything with yeast from the first day to the seventh day will be cut off from Israel.
The first and the seventh days are set aside as holy; do no work on those days. Only what you have to do for meals; each person can do that.
"Keep the Festival of Unraised Bread! This marks the exact day I brought you out in force from the land of Egypt. Honor the day down through your generations, a fixed festival to be observed always.
In the first month, beginning on the fourteenth day at evening until the twenty-first day at evening, you are to eat unraised bread.
For those seven days not a trace of yeast is to be found in your houses. Anyone, whether a visitor or a native of the land, who eats anything raised shall be cut off from the community of Israel.
Don't eat anything raised. Only matzoth."
Moses assembled all the elders of Israel. He said, "Select a lamb for your families and slaughter the Passover lamb.
Take a bunch of hyssop and dip it in the bowl of blood and smear it on the lintel and on the two doorposts. No one is to leave the house until morning.
God will pass through to strike Egypt down. When he sees the blood on the lintel and the two door posts, God will pass over the doorway; he won't let the destroyer enter your house to strike you down with ruin.
"Keep this word. It's the law for you and your children, forever.
When you enter the land which God will give you as he promised, keep doing this.
And when your children say to you, 'Why are we doing this?'
tell them: 'It's the Passover-sacrifice to God who passed over the homes of the Israelites in Egypt when he hit Egypt with death but rescued us.'" The people bowed and worshiped.
The Israelites then went and did what God had commanded Moses and Aaron. They did it all.