וּלְצֶ֧לַע הַמִּשְׁכָּ֛ן הַשֵּׁנִ֖ית לִפְאַ֣ת צָפ֑וֹן עָשָׂ֖ה עֶשְׂרִ֥ים קְרָשִֽׁים׃
And for the second side of the tabernacle, on the north side, he made twenty boards,
Read kabbalistic (mystical) interpretation of Exodus 36:25: and classical mystical sources.