the firstling
Deuteronomy 15:19-22
19
All the firstling males that come of thy herd and of thy flock thou shalt sanctify unto the LORD thy God: thou shalt do no work with the firstling of thy bullock, nor shear the firstling of thy sheep.
20
Thou shalt eat it before the LORD thy God year by year in the place which the LORD shall choose, thou and thy household.
21
And if there be any blemish therein, as if it be lame, or blind, or have any ill blemish, thou shalt not sacrifice it unto the LORD thy God.
22
Thou shalt eat it within thy gates: the unclean and the clean person shall eat it alike, as the roebuck, and as the hart.
thou shalt
Exodus 29:16
And thou shalt slay the ram, and thou shalt take his blood, and sprinkle it round about upon the altar.
Leviticus 3:2-5
2
And he shall lay his hand upon the head of his offering, and kill it at the door of the tabernacle of the congregation: and Aaron's sons the priests shall sprinkle the blood upon the altar round about.
3
And he shall offer of the sacrifice of the peace offering an offering made by fire unto the LORD; the fat that covereth the inwards, and all the fat that is upon the inwards,
4
And the two kidneys, and the fat that is on them, which is by the flanks, and the caul above the liver, with the kidneys, it shall he take away.
5
And Aaron's sons shall burn it on the altar upon the burnt sacrifice, which is upon the wood that is on the fire: it is an offering made by fire, of a sweet savour unto the LORD.