one male goat for a sin offering;
We have here an account of the great solemnity of dedicating the altars, both that of burnt-offerings and that of incense; they had been sanctified before, when they were anointed (Lev 8:10, Lev 8:11), but now they were handselled, as it were, by the princes, with their free-will offerings.
Commenting on Numbers 7:10-89
One kid of the goats for a sin offering. Though these offerings of the princes were by way of thanksgiving, and to express their joy and gladness at the erection of the tabernacle, its altars, and the service thereof; yet as this might not be without sin, which attends the best and purest performances of men, a sin offering was required, teaching us to look...
Num 7:12-88 All the princes brought the same gifts. The order in which the twelve princes, whose names have already been given at Num 1:5-15, made their presentation, corresponded to the order of the tribes in the camp (ch. 2), the tribe-prince of Judah taking the lead, and the prince of Naphtali coming last.
Commenting on Numbers 7:12-88