Leviticus 1:2-3

Speak unto the children of Israel, and say unto them, If any man of you bring an offering unto the LORD, ye shall bring your offering of the cattle, even of the herd, and of the flock. If his offering be a burnt sacrifice of the herd, let him offer a male without blemish: he shall offer it of his own voluntary will at the door of the tabernacle of the congregation before the LORD.