Exodus 26:21

18 You shall make the frames for the tabernacle: twenty frames for the south side; 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; 20 and for the second side of the tabernacle, on the north side twenty frames, 21 and their forty bases of silver, two bases under one frame, and two bases under the next frame. 22 And for the rear of the tabernacle westward you shall make six frames. 23 And you shall make two frames for corners of the tabernacle in the rear; 24 they shall be separate beneath, but joined at the top, at the first ring. Thus shall it be with both of them; they shall form the two corners.