Exodus 36:23 (KJV)

And he made fifty taches of brass to couple the tent together, that it might be one.

And he made a covering for the tent of rams' skins dyed red, and a covering of badgers' skins above that.

And he made boards for the tabernacle of shittim wood, standing up.

The length of a board was ten cubits, and the breadth of a board one cubit and a half.

One board had two tenons, equally distant one from another: thus did he make for all the boards of the tabernacle.

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 for the other side of the tabernacle, which is toward the north corner, he made twenty boards,

And their forty sockets of silver; two sockets under one board, and two sockets under another board.

And for the sides of the tabernacle westward he made six boards.

And two boards made he for the corners of the tabernacle in the two sides.