Exodus 33:19

And he said, I will make all My goodness pass before thee, He would reveal Himself in the greatness of His excellence, and I will proclaim the name of the Lord before thee, He would call out, explain to Him, Jehovah's name; and will be gracious to whom I will be gracious, and will show mercy on whom I will show mercy. The entire revelation, as promised to Moses, was an act of God's free grace and mercy, upon which no man, not even Moses, could lay claim.