24 and made forty silver bases to go under them—two bases for each frame, one under each projection.

Read Exodus 36:24 Using Other Translations

And forty sockets of silver he made under the twenty boards; two sockets under one board for his two tenons, and two sockets under another board for his two tenons.
And he made forty bases of silver under the twenty frames, two bases under one frame for its two tenons, and two bases under the next frame for its two tenons.
He also made forty silver bases—two bases under each frame, with the pegs fitting securely into the bases.