And thus did the sages of the Mishnah establish:lxxSee Mishnah Sukkah 3:6 and BT Sukkah 35b ‘If its peduncle [Var. its nipple ] was removed, and if scarring had risen over most of it, it is unfit’, – because it the etrog is like the Shekhinah, of which it is stated: (Song. 4:7) All of you is beautiful, my beloved, and there is no defect in ‘her’ you.
Date-palm fronds – this is the lulav. And upon it is stated:lxxiMishnah Sukkah 3:1 ‘if its leaves are separated, it is unfit’, because he is one who ‘cuts off the shoots’, [for behold the lulav is the binding and the unity of all] whoever makes a blessing over it such a lulav on the first day of Sukkot. Because it the lulav is the binding and unity of all, the ‘ḥaiy (life-force, =18) of the worlds’, which corresponds to the 18∞ḥaiy vertebrae of the spine. And because of this, the sages of the Mishnah established:lxxiiVayiqra Rabbah 30:14 ‘the lulav (palm-branch) is like a spine’.