וּשְׁנֵ֤י קְרָשִׁים֙ תַּעֲשֶׂ֔ה לִמְקֻצְעֹ֖ת הַמִּשְׁכָּ֑ן בַּיַּרְכָתָֽיִם׃
And two boards shalt thou make for the corners of the tabernacle in the hinder part.
Read kabbalistic (mystical) interpretation of Exodus 26:23: and classical mystical sources.