John Gills Exposition of the Bible Commentary - Exodus 30:10
And Aaron shall make an atonement upon the horns of it once in a year ,.... On the day of atonement, as the Targum of Jonathan, and so Jarchi and Aben Ezra explain it; and the atonement here referred to seems to be an atonement for the altar itself, see Leviticus 16:18 and as the altar of burnt offering was first expiated and then used, Exodus 29:36 so it seems the altar of incense had not only an atonement made on it, but for it: and this was done with the blood of the sin offering... read more
Matthew Henry's Complete Commentary - Exodus 30:1-10
I. The orders given concerning the altar of incense are, 1. That it was to be made of wood, and covered with gold, pure gold, about a yard high and half a yard square, with horns at the corners, a golden cornice round it, with rings and staves of gold, for the convenience of carrying it, Exod. 30:1-5. It does not appear that there was any grate to this altar for the ashes to fall into, that they might be taken away; but, when they burnt incense, a golden censer was brought with coals in it,... read more