Another matter: “Hear Israel” (Deuteronomy 6:4) – this is what the verse said: “Whom else do I have in heaven? And besides You, I desire nothing on earth” (Psalms 73:25). Rav said: There are two firmaments: The heavens and the heavens of the heavens. Rabbi Elazar said: There are seven firmaments: The heavens, the heavens of heavens, Rakia, Sheĥakim, Maon, Zevul, Arafel.
The Holy One blessed be He opened them all for Israel, to inform them that there is no God other than He. The Assembly of Israel said before the Holy One blessed be He: ‘Master of the universe, who do I have in Heaven other than [You, in] Your glory? Just as I have no one in heaven other than You, so I have not desired another [god] on earth; just as I have not associated any other god with You in Heaven, so I did not associate any other god with You on earth.
Rather, each day I enter synagogues and attest that there is no god other than You, and I say: “Hear, Israel: The Lord is our God, the Lord is one”’ (Deuteronomy 6:4).