(Ibid.) "that from the heavens I spoke to you": One verse states "that from the heavens, etc.", and another (Ibid. 19:20) "And the L–rd went down upon Mount Sinai!" How are these two verses to be reconciled? A third verse reconciles them, viz. (Devarim 4:36) "From the heavens He made you hear His voice to exhort you, and on the earth He showed you His great fire, and His works you heard from the midst of the fire." These are the words of R. Yishmael.
Was God in Heaven or on the Mountain
Mekhilta Tractate Bachodesh 9:22