Exodus 26:16-18

Amplified Bible

¹⁶ The length of each board shall be ten cubits and the width of each board shall be one and a half cubits. ¹⁷ Make two dovetails in each board for fitting [them] together; you shall do the same for all the tabernacle boards. ¹⁸ You shall make the boards for the tabernacle [in the following quantities]: twenty boards for the south side.