Midrash su Salmi 22:30

12) "from the tent of meeting": I might think (that the voice came) from the whole house; it is, therefore, written: "from above the kapporeth." If "from above the kapporeth," I might think from above the entire kapporeth; it is, therefore, written: "from between the two cherubs." These are the words of R. Akiva. R. Shimon b. Azzai said: I come not to dispute the words of the master, but to add to them. That great glory, of which it is written, "Do I not fill heaven and earth?" — see how His love of Israel wrought upon this glory! The L–rd, as it were, contracted Himself to speak from above the kapporeth between the two cherubs! R. Dossa says: It is written (Shemoth 33:20): "For a man shall not see Me and live." (Even the holy creatures who bear the Throne of Glory do not behold His glory.) — In their life they do not see (Him), but they see (Him) in their death. And thus is it written (Psalms 22:30): "Before Him (i.e., before His manifest glory) shall bow down all who descend to the dust, when his (i.e., a man's) soul no longer animates (the body" [but departs from it.]). R. Shimon said: I come not to dispute the words of the master, but to add to them: "For a man shall not see Me, and the living" — Even the angels, whose lives are eternal, do not behold the glory.