Leviticus 3
This is the last of the freewill offerings. Like the Burnt offering it was the sacrifice of animals; like the meal offering or Minchah it was in part to be eaten. As with the former, the offerer laid his hand on the head of his offering, and slaughtered it at the entrance of the tent of meeting; and Aaron's sons the priests scattered rather than sprinkled the blood on the altar round about. It was, of course, presented like the Burnt offering before Jehovah; but no more than the fat that covers the inwards, and also the fat that is on the inwards, and the two kidneys, and the fat that is on them which is by the flank, and the net or caul upon the liver was to be taken away as far as the kidneys and burnt on the altar. The special feature of this offering, the Shelem, was to complete, as the cognate verb means. The aim was to express communion; and this it did with fullness indeed if we knew not who He is that inspired these communications through His servant Moses.
In the law of the sacrifice of peace offerings (Lev. 7:11-21) we find this distinction in point of character or motive. They might be offered for a thanksgiving with their appropriate unleavened cakes mingled with oil, and unleavened wafers anointed with oil, and cakes mingled with oil, of fine flour soaked, but not without cakes of leavened bread also; for man's taint is in his rendering of thanks. In this case the flesh of the sacrifice had to be eaten on the day of the offering, and none of it was to be left until the morning. But if the sacrifice of this offering were a vow or a voluntary offering, not only the flesh might be eaten on the day that it was presented, but the remainder of it on the morrow also, though the rest, if any, must be burnt on the third day. For if eaten then, so far from being accepted, it should be imputed an abomination to the offeror, and he that eat of it should bear his iniquity, just as uncleanness upon the eater would bring on him cutting off from his people. Thanksgiving is simple, and looked for from the simplest believer; but it has no such sustaining power as that devotedness of heart which Christ and His sacrifice more deeply known create in some that know God's grace better. There is no real communion apart from faith in Christ's sacrifice and the thanksgiving it calls forth. Separate from Him and the faith that owns His work, it is fleshly, abominable to God, and ruinous to man; but the energy of the Spirit which fills the heart with Christ and forms devotedness has greater permanence, and it produces greater vigilance against all that defiles, though this in principle is true of those born of God, however feeble they may be.
It is in the appendix of the same chapter (Lev. 7:28-34) that we find the distinctive communion that belonged to the peace offering. The offeror’s own hands were to bring the first offering to Jehovah. The breast, for Aaron and his sons, was to be waved before Jehovah, as the fat was to be burnt upon the altar. The right shoulder was to be as a peace offering to the offering priest. The rest was for the offeror, his family or friends. Thus Jehovah had His portion, Christ as signified by the priest that presented the blood and the fat, He and His house (“whose house are we”), and the believers one with another, all entering into and enjoying the fellowship of Christ's work. But all uncleanness is peremptorily treated as incompatible with the feast on that sacrifice. If man's communion be prominent, the more care is taken that he forget not what is due to God and His holiness.