Exodus 26:19

and forty bases of silver you shall make under the twenty frames , two bases under one frame for its two tenons , and two bases under the next frame for its two tenons ;

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

And thou shalt make forty sockets of silver under the twenty boards; two sockets under one board for his two tenons, and two sockets under another board for his two tenons.