Exodus 33:19, (ESV)
19 And he said, “I will make all my goodness pass before you and will proclaim before you my name ‘The Lord.’ And I will be gracious to whom I will be gracious, and will show mercy on whom I will show mercy.

Exodus 34:6-7, English Standard Version (ESV)
6 The Lord passed before him and proclaimed, “The Lord, the Lord, a God merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness, 7 keeping steadfast love for thousands,[a] forgiving iniquity and transgression and sin, but who will by no means clear the guilty, visiting the iniquity of the fathers on the children and the children’s children, to the third and the fourth generation.”