Albert Barnes Commentary Leviticus 1:3

"If his oblation be a burnt-offering of the herd, he shall offer it a male without blemish: he shall offer it at the door of the tent of meeting, that he may be accepted before Jehovah." — Leviticus 1:3 (ASV)

burnt - literally, that (offering) which ascends (as a flame).

A male without blemish - Males were required in most offerings, being the stronger sex which takes precedence over the other. But females were allowed in peace-offerings (Leviticus 3:1; Leviticus 3:6), and were expressly prescribed in the sin-offerings of the common people (Leviticus 4:28; Leviticus 4:32; Leviticus 5:6).

At the door of the tabernacle of the congregation - Wherever these words occur, they should be rendered: “at the entrance of the tent of meeting.” The place denoted is that part of the court in front of the tabernacle, where the brass altar and the laver stood, and where alone sacrifices could be offered. See the illustration for Exodus 26 (Exodus 26).