Exodus 26:15

13The cubit on the one side and the cubit on the other side, of that which remains in the length of the curtains of the tent, shall hang over the sides of the tabernacle on this side and on that side, to cover it.

14You shall make a covering for the tent of rams’ skins dyed red, and a covering of sea cow hides above.

15“You shall make the boards for the tabernacle of acacia wood, standing upright.

16Ten cubits shall be the length of a board, and one and a half cubits the width of each board.

17There shall be two tenons in each board, joined to one another: thus you shall make for all the boards of the tabernacle.