Exodus 26:19-21

LITV(i) 19 And you shall make forty sockets of silver for the twenty boards; two sockets under the one board for its two pins, and two sockets under the one board for its two pins . 20 And for the second side of the tabernacle, on the north side twenty boards; 21 and their forty silver sockets; two sockets under the one board, and two sockets under the one board.