Exodus 26:18-21

18You shall make the frames for the tabernacle: twenty frames for the south side;

19and 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;

20and for the second side of the tabernacle, on the north side twenty frames,

21and their forty bases of silver, two bases under one frame, and two bases under the next frame.