A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
lev 1:1BURNT OFFERINGS OF THE HERD. (Lev. 1:1-17)
the Lord . . . spake . . . out of the tabernacle--The laws that are contained in the previous record were delivered either to the people publicly from Sinai, or to Moses privately, on the summit of that mountain; but on the completion of the tabernacle, the remainder of the law was announced to the Hebrew leader by an audible voice from the divine glory, which surmounted the mercy seat.
lev 1:2Speak unto the children of Israel, and say unto them--If the subject of communication were of a temporal nature, the Levites were excluded; but if it were a spiritual matter, all the tribes were comprehended under this name (Deu 27:12).
If any man of you bring an offering unto the Lord--The directions given here relate solely to voluntary or freewill offerings--those rendered over and above such, as being of standing and universal obligation, could not be dispensed with or commuted for any other kind of offering (Exo 29:38; Lev 23:37; Num 28:3, Num. 28:11-27, &c.).
bring your offering of the cattle, &c.--that is, those animals that were not only tame, innocent and gentle, but useful and adapted for food. This rule excluded horses, dogs, swine, camels, and asses, which were used in sacrifice by some heathen nations, beasts and birds of prey, as also hares and deers.
lev 1:3a burnt sacrifice--so called from its being wholly consumed on the altar; no part of it was eaten either by the priests or the offerer. It was designed to propitiate the anger of God incurred by original sin, or by particular transgressions; and its entire combustion indicated the self-dedication of the offerer--his whole nature--his body and soul--as necessary to form a sacrifice acceptable to God (Rom 12:1; Phi 1:20). This was the most ancient as well as the most conspicuous mode of sacrifice.
a male without blemish--No animal was allowed to be offered that had any deformity or defect. Among the Egyptians, a minute inspection was made by the priest; and the bullock having been declared perfect, a certificate to that effect being fastened to its horns with wax, was sealed with his ring, and no other might be substituted. A similar process of examining the condition of the beasts brought as offerings, seems to have been adopted by the priests in Israel (Joh 6:27).
at the door of the tabernacle--where stood the altar of burnt offering (Exo 40:6). Every other place was forbidden, under the highest penalty (Lev 17:4).
lev 1:4shall put his hand upon the head--This was a significant act which implied not only that the offerer devoted the animal to God, but that he confessed his consciousness of sin and prayed that his guilt and its punishment might be transferred to the victim.
and it shall be--rather, "that it may be an acceptable atonement."
lev 1:5he shall kill the bullock--The animal should be killed by the offerer, not by the priest, for it was not his duty in case of voluntary sacrifices; in later times, however, the office was generally performed by Levites.
before the Lord--on the spot where the hands had been laid upon the animal's head, on the north side of the altar.
sprinkle the blood--This was to be done by the priests. The blood being considered the life, the effusion of it was the essential part of the sacrifice; and the sprinkling of it--the application of the atonement--made the person and services of the offerer acceptable to God. The skin having been stripped off, and the carcass cut up, the various pieces were disposed on the altar in the manner best calculated to facilitate their being consumed by the fire.
lev 1:8the fat--that about the kidneys especially, which is called "suet."
lev 1:9but his inwards and his legs shall he wash in water, &c.--This part of the ceremony was symbolical of the inward purity, and the holy walk, that became acceptable worshippers.
a sweet savour unto the Lord--is an expression of the offerer's piety, but especially as a sacrificial type of Christ.
lev 1:10if his offering be of the flocks--Those who could not afford the expense of a bullock might offer a ram or a he-goat, and the same ceremonies were to be observed in the act of offering.
lev 1:14if the burnt sacrifice . . . be of fowls--The gentle nature and cleanly habits of the dove led to its selection, while all other fowls were rejected, either for the fierceness of their disposition or the grossness of their taste; and in this case, there being from the smallness of the animal no blood for waste, the priest was directed to prepare it at the altar and sprinkle the blood. This was the offering appointed for the poor. The fowls were always offered in pairs, and the reason why Moses ordered two turtledoves or two young pigeons, was not merely to suit the convenience of the offerer, but according as the latter was in season; for pigeons are sometimes quite hard and unfit for eating, at which time turtledoves are very good in Egypt and Palestine. The turtledoves are not restricted to any age because they are always good when they appear in those countries, being birds of passage; but the age of the pigeons is particularly marked that they might not be offered to God at times when they are rejected by men [HARMER]. It is obvious, from the varying scale of these voluntary sacrifices, that the disposition of the offerer was the thing looked to--not the costliness of his offering.