Charles Ellicott Commentary Exodus 30:4

"And two golden rings shalt thou make for it under the crown thereof; upon the two ribs thereof, upon the two sides of it shalt thou make them; and they shall be for places for staves wherewith to bear it." — Exodus 30:4 (ASV)

Two golden rings. —The golden altar was so much smaller and lighter than the brazen one that only two rings were required for carrying it, instead of the “four rings” needed by the brazen altar (Exodus 27:4).

By the two corners thereof. —Rather, on the two sides thereof. The word used means, literally, “ribs,” and is explained in the following clause.