It is Thou who hast revealed thy secret to Moses and who hast not concealed from him any of Thy mighty works. When the words goeth not forth from Thy mouth all the lofty mountains trembled and stood before Thee in great consternation; when the word goeth forth from Thy mouth they were all of them burned with flames of fire. It is Thou who examinest the inward parts and choosest the faithful. Thou dwellest in the flame of rivers of fire and conflagrations. It is Thou who art mighty, more lofty than all the lofty and lifted up above all, who dost cast down the haughty and exaltest the humble.
Moses and the Secret Teaching of Thou
Heikhalot Rabbati 27:1