Targum for Exodus 26:22

וּֽלְיַרְכְּתֵ֥י הַמִּשְׁכָּ֖ן יָ֑מָּה תַּעֲשֶׂ֖ה שִׁשָּׁ֥ה קְרָשִֽׁים׃

And for the hinder part of the tabernacle westward thou shalt make six boards.

Targum Jonathan on Exodus