Exodus 26:17-19

Amplified Bible

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. ¹⁹ You shall make forty silver sockets under the twenty boards, two sockets under each board for its two dovetails, and two sockets under another board for its two dovetails;