Exodus 26:18 (KJV)

And a cubit on the one side, and a cubit on the other side of that which remaineth in the length of the curtains of the tent, it shall hang over the sides of the tabernacle on this side and on that side, to cover it.

And thou shalt make a covering for the tent of rams' skins dyed red, and a covering above of badgers' skins.

And thou shalt make boards for the tabernacle of shittim wood standing up.

Ten cubits shall be the length of a board, and a cubit and a half shall be the breadth of one board.

Two tenons shall there be in one board, set in order one against another: thus shalt thou make for all the boards of the tabernacle.

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.

And for the second side of the tabernacle on the north side there shall be 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 thou shalt make six boards.

And two boards shalt thou make for the corners of the tabernacle in the two sides.