Leviticus 16:8

“And Aaron shall cast lots on the two goats; one lot for Yahweh, and the other lot for ‘azazel.”

Then he casts lots for them, selecting between the two, for one is to be for Yahweh, and one is to be for ‘azazel. The word ‘az'azel is a puzzle to us. Some see it as meaning ‘the goat of a complete going away' (from the piel of 'azal - to go away and ‘ez - a goat), thus indicating the complete going away of sin. Others that it means ‘in order to completely remove' (compare Arabic ‘azala), thus indicating the complete removal of sin. Still others consider that it refers to a desolate region, a stark and deserted place, or a precipice as in later Talmudic tradition (compare Leviticus 16:22), and others see it as representing the name of a demon of the desert named ‘Azazel (a name, however, that is found nowhere else until the much later tradition derived from its use here).

This he-goat is somewhat like the living bird in the ritual of cleansing from suspicious skin disease (Leviticus 14:7; also Leviticus 14:53) which went into ‘the countryside', where there was no suggestion of a demon. Thus the indication would seem to be that the he-goat also is sent away to some far place where it can disappear for ever, not that it is sent to a demon. However, those disposed to accept such an interpretation need to recognise that the idea would be that their sins were sent back to the one responsible for them (one connected with the serpent), not that an offering is being made to him. This is made clear by the significance of the ritual and by the fact that it is not slaughtered. But in view of its close link with the other he-goat with which it is identified as part of a purification for sin offering (Leviticus 16:5) this interpretation just does not fit the bill. The two he-goats were seen as one combined purification for sin offering, and all of a purification for sin offering goes to Yahweh in one way or another.

Thus one of the remaining three explanations for the word is more likely. The idea behind the other three is really the same. The goat and the sins will be gone for ever from the camp to return no more (see verse 16), as with the living bird. The whole purpose is that Israel might know that their sins and uncleannesses up to that point have gone for ever. Many centuries later the tradition would grow that it was taken to a precipice and thrown off, but that would conflict with the parallel of the freed bird.