Exodus 26:17 in the King James Version
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.
Context
16 Ten cubits shall be the length of a board, and one and a half cubits the width of each board.
17 There shall be two tenons in each board, joined to one another: thus you shall make for all the boards of the tabernacle.
18 You shall make twenty boards for the tabernacle, for the south side southward.