John Gill Commentary Leviticus 16:25

"And the fat of the sin-offering shall he burn upon the altar." — Leviticus 16:25 (ASV)

And the fat of the sin offering shall he burn upon the
altar .
] The brazen altar of burnt offering, and so says Jarchi, on the outward altar; for of the inward (i.e. the altar of incense) it is written, you shall not offer upon it strange incense, nor a burnt offering, nor a meat offering; and this fat he explains to be what was on the inwards of both the bullock and the goat; and so says Aben Ezra, the fat of the bullock for the sin offering, and the fat of the goat for a sin offering, and also the fat of the kid of the goat, which, was a sin offering for the priest, (Numbers 29:11) ; this fat was burnt at the same time the burnt offerings were offered in (Leviticus 16:24) .