Treasury of Scripture Knowledge
But the firstling of a cow, or the firstling of a sheep, or the firstling of a goat, thou shalt not redeem; they are holy: thou shalt sprinkle their blood upon the altar, and shalt burn their fat for an offering made by fire, for a sweet savour unto the LORD.
All the first males to come to birth in your herd and your flock are to be holy to the Lord your God: the first birth of your ox is not to be used for work, the wool of your first lamb is not to be cut.
Then let it be put to death, so that the sides of the altar are marked with its blood.
And he is to put his hand on the head of his offering and put it to death at the door of the Tent of meeting; and Aaron's sons, the priests, are to put some of the blood on and round the altar.