Albert Barnes Commentary Leviticus 1:2

"Speak unto the children of Israel, and say unto them, When any man of you offereth an oblation unto Jehovah, ye shall offer your oblation of the cattle, [even] of the herd and of the flock." — Leviticus 1:2 (ASV)

Speak to the children of Israel - It is important to observe that these first instructions (Leviticus 1:2–17) are addressed expressly to the individual who felt the need of sacrifice on his own account. They were not delivered through the priests, nor did the officiating priest have any choice as to what he was to do. He was only to examine the victim to see that it was perfect (Leviticus 22:17–24), and to perform other strictly prescribed duties (Leviticus 6:8–21). The act of offering was to be voluntary on the part of the worshipper, but the mode of doing it was in every point defined by the Law. The presenting of the victim at the entrance of the tabernacle was in fact a symbol of free will submitting itself to the Law of the Lord.

Such acts of sacrifice are to be distinguished from the public offerings and those ordained for individuals on special occasions (see Leviticus 4:2 note), which belonged to the religious education of the nation.

Offering - Hebrew: קרבן qorbân - the general name for what was formally given up to the service of God , and exactly corresponding to the words “offering” and “oblation.”