לֹֽא־תִטַּ֥ע לְךָ֛ אֲשֵׁרָ֖ה כׇּל־עֵ֑ץ אֵ֗צֶל מִזְבַּ֛ח יְהֹוָ֥ה אֱלֹהֶ֖יךָ אֲשֶׁ֥ר תַּעֲשֶׂה־לָּֽךְ׃
You shall not set up a sacred post — any kind of pole beside the altar of the Eternal your God that you may make.
Torah Temimah points to Tamid 28b.
תניא, ר׳ אליעזר בן יעקב אומר, מניין שאין עושין אכסדראות בעזרה, שנאמר לא תטע לך אשרה כל עץ אצל מזבח ה׳ הכי קאמר לא תטע לך אשרה – לא תטע לך כל עץ אצל מזבח ה׳.
English: It was taught: Rabbi Eliezer ben Yaakov says, From where do we know that one may not build colonnades in the Temple courtyard? From the verse “You shall not plant for yourself an asherah — any tree beside the altar of the Eternal.” Thus the verse means: You shall not plant for yourself an asherah; [and] you shall not plant for yourself any tree beside the altar of the Eternal.
The verse is extended by asmakhta to prohibit any wooden structure in the Temple courtyard, not only an asherah tree.
Derash on the verse (Bavli / Tannaitic) — not a formal named middah of the 13. The words “kol etz” are read as a separate prohibition of any tree or wooden structure near the altar.
No wooden structures or trees of any kind may be erected in the Temple courtyard beside the altar.