"In the ninth book I will include commandments regarding sacrifices by individuals. And I have called this book the Book of Sacrifices."

50. The Passover Sacrifice - Korban Pesach

We are commanded to offer the Passover sacrifice, a male lamb or kid, on the afternoon of the 14th of Nisan [as it says "You shall take of the lambs or of the kids a male in its first year and guard it until the 14th of this month, and all the congregation of Israel shall slaughter it in the afternoon"¹]. One should bring peace-offerings at the same time, as it says "And you shall slaughter a Passover, sheep and cattle, to Ha-Shem your G-d".² It is forbidden for anyone who has leaven in his possession to participate in it, as it says "You shall not slaughter the blood of my sacrifice on leaven".³ It is forbidden to leave overnight the parts of it that are supposed to be burned on the altar, as it says "And the fat of my festival shall not lie over until morning".³ If a person is impure or far away [from the Temple] on the 14th of Nisan he must offer a Passover sacrifice on the 14th of Iyar [as it says "If any man is unclean... or on a far journey... he shall make a Passover to Ha-Shem; in the second month on the 14th day in the afternoon they shall make it"⁴].^a

We are commanded to eat the Passover sacrifice on the evening of the 15th (of Nisan or Iyar), as it says "And they shall eat the flesh on that night roasted; with unleavened bread and bitter herbs they shall eat it".^5,4 It is forbidden to eat it singed or boiled, as it says "You shall not eat of it singed or boiled in water, but only roasted".⁶ That of the 14th of Nisan can only be eaten by the group that is participating in it and it is forbidden to take any of it elsewhere, as it says "[In one house it shall be eaten]; you shall not take any of the flesh outside of the house".⁷ It is forbidden to give any of it to an apostate or a non-Jew, as it says "[This is the law of the Passover: no stranger shall eat of it]... a dweller or hired laborer shall not eat of it".⁸ It is forbidden for an uncircumcised man or one who has uncircumcised children or slaves to eat it, as it says "And you shall circumcise him; then he shall eat of it... circumcise all his males and then he shall come near to make it... and no uncircumcised man shall eat of it".⁹ It is forbidden to break its bones, as it says "And you shall not break a bone in it".¹⁰ It is forbidden to leave any of its flesh over until morning, and if any is left it must be burned, as it says "And you shall not leave any of it until morning, and what is left over of it until morning you shall burn in the fire"¹¹; and it says "They shall not leave any of it until morning".¹² The peace-offerings brought with it must not be left over to the morning of the 16th, as it says "And the flesh that you slaughter in the evening shall not lie over... to the morning".^13,b

Sources:
1. Ex. 12:5-6	a. 1:1,5,7; 5:1; 10:12,15
2. Deut. 16:2	b. 5:5; 8:1,3-4; 9:1,7-9; 10:1,11,13
3. Ex. 23:18; see 34:26
4. Num. 9:10-11
5. Ex. 12:8
6. Ex. 12:9
7. Ex. 12:46
8. Ex. 12:43,45
9. Ex. 12:44,48
10. Ex. 12:46; Num. 9:12
11. Ex. 12:10
12. Num. 9:12
13. Deut. 16:4