A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown [1882] at sacred-texts.com
If a soul sin, and commit a trespass against the Lord--This law, the record of which should have been joined with the previous chapter, was given concerning things stolen, fraudulently gotten, or wrongfully kept. The offender was enjoined to make restitution of the articles to the rightful owner, along with a fifth part out of his own possessions. But it was not enough thus to repair the injury done to a neighbor and to society; he was required to bring a trespass offering, as a token of sorrow and penitence for having hurt the cause of religion and of God. That trespass offering was a ram without blemish, which was to be made on the altar of burnt offerings, and the flesh belonged to the priests. This penalty was equivalent to a mitigated fine; but being associated with a sacred duty, the form in which the fine was inflicted served the important purpose of rousing attention to the claims and reviving a sense of responsibility to God.
THE LAW OF THE BURNT OFFERING. (Lev 6:8-13)
Command Aaron and his sons, saying, This . . . law of the burnt offering--In this passage Moses received instructions to be delivered to the priests respecting their official duties, and first the burnt offering--Hebrew, "a sacrifice, which went up in smoke." The daily service consisted of two lambs, one offered in the morning at sunrise, the other in the evening, when the day began to decline. Both of them were consumed on the altar by means of a slow fire, before which the pieces of the sacrifice were so placed that they fed it all night. At all events, the observance of this daily sacrifice on the altar of burnt offering was a daily expression of national repentance and faith. The fire that consumed these sacrifices had been kindled from heaven at the consecration of the tabernacle [Lev 9:24], and to keep it from being extinguished and the sacrifices from being burned with common fire, strict injunctions are here given respecting not only the removal of the ashes [Lev 6:10-11], but the approaching near to the fireplace in garments that were not officially "holy."
THE LAW OF THE MEAT OFFERING. (Lev 6:14-18)
this is the law of the meat offering--Though this was a provision for the priests and their families, it was to be regarded as "most holy"; and the way in which it was prepared was: on any meat offerings being presented, the priest carried them to the altar, and taking a handful from each of them as an oblation, he salted and burnt it on the altar; the residue became the property of the priests, and was the food of those whose duty it was to attend on the service. They themselves as well as the vessels from which they ate were typically holy, and they were not at liberty to partake of the meat offering while they labored under any ceremonial defilement.
THE HIGH PRIEST'S MEAT OFFERING. (Lev 6:19-23)
This is the offering of Aaron, and of his sons--the daily meat offering of the high priest; for though his sons are mentioned along with him, it was probably only those of his descendants who succeeded him in that high office that are meant. It was to be offered, one half of it in the morning and the other half in the evening--being daily laid by the ministering priest on the altar of burnt offering, where, being dedicated to God, it was wholly consumed. This was designed to keep him and the other attendant priests in constant remembrance, that though they were typically expiating the sins of the people, their own persons and services could meet with acceptance only through faith, which required to be daily nourished and strengthened from above.
THE LAW OF THE SIN OFFERING. (Lev 6:21-30)
This is the law of the sin offering--It was slain, and the fat and inwards, after being washed and salted, were burnt upon the altar. But the rest of the carcass belonged to the officiating priest. He and his family might feast upon it--only, however, within the precincts of the tabernacle; and none else were allowed to partake of it but the members of a priestly family--and not even they, if under any ceremonial defilement. The flesh on all occasions was boiled or sodden, with the exception of the paschal lamb, which was roasted [Exo 12:8-9]; and if an earthen vessel had been used, it being porous and likely to imbibe some of the liquid particles, it was to be broken; if a metallic pan had been used it was to be scoured and washed with the greatest care, not because the vessels had been defiled, but the reverse--because the flesh of the sin offering having been boiled in them, those vessels were now too sacred for ordinary use. The design of all these minute ceremonies was to impress the minds, both of priests and people, with a sense of the evil nature of sin and the care they should take to prevent the least taint of its impurities clinging to them.