Numbers 18:19

God gave the service of the Levites, and the Levites themselves, as a gift to the priests. Priesthood too was a pure gift to Aaron and his sons. Because of the anointing, He gave them the most holy things to eat, and this was a special privilege of the priests. The same is true for us.

The whole character of priesthood in question here (Numbers 18) is grace. After the murmuring of the people of Israel, God took the rod from Aaron's hand, to lead the people across the desert Himself. The love of God is greater than the sin of the people. Without that they would never have been able to cross the desert. Aaron's rod is therefore the complete display of the grace of God.

The idea behind a heave offering was taking up a part to offer it to God. The idea of the wave offering is wider. It implies setting the gift apart for God, since it was waved before the Lord. So a gift might be called both a heave offering and a wave offering. But not every wave offering could be called a heave offering. To heave, you needed a larger amount to lift the part out of. To wave, you needed only the gift itself.

The daughters of Aaron were not to eat of the sin offerings or the trespass offerings. God provided for them to the fullest limit of their capacity. But there were certain functions they could not carry out. Certain privileges lay beyond their range. Certain responsibilities were too heavy for them to bear... We must be ready for these varied measures among the members of the priestly household. We are all, blessed be God, on the same ground. We all stand in the same title. We are all in the same relationship. But our capacities vary.

The covenant of salt refers to a very ancient custom. A host would welcome a guest into his tent, and the guest would eat salt with him. From then on the host's duty to that guest was sacred and could not be broken.

And so we read of "a covenant of salt," expressing in figure what was to be kept unbroken and unchanging (Num. 18:19; 2 Chron. 13:5). So the Lord, in Mark 9:49-50, declares, "Everyone will be salted with fire. Salt is good, but if the salt has lost its saltiness, how will you make it salty again? Have salt in yourselves, and be at peace with one another." If fire stands for God's avenging judgment of evil, salt just as clearly stands for His preserving power in relation with Himself.

It is "the salt of the covenant of your God." In it God, as it were, binds Himself to bless us according to His own heart. The ground of this is the everlasting power of the sacrifice of the Lord Jesus... The sweet savour of what Christ was to God here as man on earth will be no passing savour. It will last for all eternity.

It is a covenant that cannot be dissolved or broken. The reward of the priest and his house must be applied to the reward Christ has — the joy that is His, His people and His house sharing it with Him... Aaron had no inheritance in the land. His inheritance is the Lord. "I am your portion and your inheritance among the people of Israel." The Levites had no inheritance in the land, but received tithes. Aaron's was the better portion, and so is ours in Christ.