This was the dedication offering for the altar on the day when it was anointed, from the chiefs of Israel: twelve silver plates, twelve silver basins, twelve golden dishes,
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
This was the dedication of the altar--The inspired historian here sums up the separate items detailed in the preceding narrative, and the aggregate amount is as follows: 12 silver chargers, each weighing 130 shekels equals 1560; 12 silver bowls, each 70 shekels equals 840: total weight.
This [was] the dedication of the altar, in the day when it was anointed, by the princes of Israel: twelve chargers of silver, twelve silver bowls, twelve spoons of gold: (f) This was the offering of the princes, when Aaron dedicated the altar.