And one needs to bow in all of them with the 18∞ḥaiy vertebrae of the spine, which correspond to the eighteen blessings,cxxxVayiqra Rabbah 1:8 which are incorporated into the life-force∞ḥaiy (=18) of the worlds.
And this is what the Masters of the Mishnah enacted:cxxxiBT Berakhot 28b ‘until all the vertebrae of the spine are loosened’.
And the spine is a palm-shoot (lulav).cxxxiiVayiqra Rabbah 30:14 If its leaves become spread, it is invalid.cxxxiiiMishnah Sukkah 3:1
In similar fashion, one must not interrupt the eighteen blessings of prayer, which correspond to the 18 ‘shakings’ of the lulav. As the Masters of the Mishnah have established:cxxxivBT Berakhot 30b ‘even if a snake is wound about his ankle, he should not interrupt’.