Peter Pett's Commentary on the Bible
Leviticus 4 - Introduction
The Purification for Sin Offering (Leviticus 4:1 to Leviticus 5:13).
Chapter 4 The Purification for Sin Offering (chatta'ah).
Now we are introduced to the purification for sin and the guilt/trespass sacrifices. The form chatta'ah comes from a verbal stem meaning ‘to purify'. It deals with sin as a whole. The guilt/trespass offerings are also purification for sin offerings but deal with particular breaches of the covenant, and are connected with compensation, and putting things right. It may be that both these were a new innovation to Israel, or it may simply be that because of their nature the histories had not had cause to mention them. But the important element in them is that they concentrate on sin, its eradication and its need for forgiveness and purification. They face the question of sin head on, and deal with the question of specific sins.
The sacrifices are at different levels dependent on whose sin they deal with. So the major purification for sin offerings are those for the sins of the priests, who are representatives of ‘the congregation (church, assembly) of Israel', and of the community as a whole, which of course therefore contains within it the priests. The priests are holy to God, and the whole community are to God ‘a kingdom of priests and a holy nation' (Exodus 19:6). Thus such sins are directly against God's holiness and cause a breach of the covenant for the whole nation.
These sins were sins against the covenant. They might be ritual failures or moral failures (both being the same in their eyes, they breached the covenant). Carelessness with regard to either would bring them under God's judgment. There must be no failure in observing God's ritual requirements exactly as required, and the keeping of Yahweh's moral commands was seen as an essential part of the ritual requirements. All of life was considered to be involved in God, and had to be lived out with God and His requirements in mind. The failure to observe the ritual correctly in mind here would be accidental or careless. To do such a thing deliberately would be presumptuous sin and would incur death.
There is, however, an important difference between purification for sin offerings and all other offerings (including guilt offerings), and that is in the application of the blood. Only in the case of the purification for sin offering is it applied to the horns of the altar, and this is said in Leviticus 8:15 to be in order to purify the altar, with the remainder cast at the foot of the altar, which in Leviticus 8:15 is said to sanctify it in order to make atonement for it.
In the case of the whole burnt offerings, the peace sacrifices and the guilt offerings the blood is ‘sprinkled round about the altar'. The general significance must be the same, but in the case of the purification for sin offering extra purification is required.