John Gill Commentary Leviticus 16:9

"And Aaron shall present the goat upon which the lot fell for Jehovah, and offer him for a sin-offering." — Leviticus 16:9 (ASV)

And Aaron shall bring the goat on which the Lord's lot fell , &c.] Alluding to the manner of taking out the lot by the high priest, who, when he took it out, lifted it up with his hand, and then let it down, and put it on the head of the goat; after which he brought it to the altar to be sacrificed:

and offer him [for] a sin offering ; an offering for the sins of the people, as a type of Christ, who made his soul an offering for sin for his people; but this was not done by Aaron until he had brought and killed the sin offering for himself; after which we read of killing this sin offering for the people, (Leviticus 16:11Leviticus 16:15) ; wherefore some take this offering here to be no other than a setting apart or devoting the goat for this service.