Deuteronomy 4:35-36

4:35 You have been taught that the Lord alone is God – there is no other besides him. 4:36 From heaven he spoke to you in order to teach you, and on earth he showed you his great fire from which you also heard his words. ¹ 

[4:36]  ¹ tn Heb “and his words you heard from the midst of the fire.”