Exodus 34:8 (KJV)

And the Lord passed by before him, and proclaimed, The Lord, The Lord God, merciful and gracious, longsuffering, and abundant in goodness and truth,

Keeping mercy for thousands, forgiving iniquity and transgression and sin, and that will by no means clear the guilty; visiting the iniquity of the fathers upon the children, and upon the children’s children, unto the third and to the fourth generation.

And Moses made haste, and bowed his head toward the earth, and worshipped.

And he said, If now I have found grace in thy sight, O Lord, let my Lord, I pray thee, go among us; for it is a stiffnecked people; and pardon our iniquity and our sin, and take us for thine inheritance.

And he said, Behold, I make a covenant: before all thy people I will do marvels, such as have not been done in all the earth, nor in any nation: and all the people among which thou art shall see the work of the Lord: for it is a terrible thing that I will do with thee.