I, even I, am he that blotteth out thy transgressions for mine own sake, and will not remember thy sins.

Wesley's Notes

43:25 I - I whom thou hast thus provoked. Mine own sake - Not for thy merits, but my own mere goodness.

Jamieson-Fausset-Brown Bible Commentary

25. I, even I-the God against whom your sin is committed, and who alone can and will pardon. (Isa 44:22).

for mine own sake-(Isa 48:9, 11). How abominable a thing sin is, since it is against such a God of grace! "Blotted out" is an image from an account-book, in which, when a debt is paid, the charge is cancelled or blotted out.

not remember . sins-(Jer 31:34). When God forgives, He forgets; that is, treats the sinner as if He had forgotten his sins.

Matthew Henry's Concise Commentary

43:22-28 Those who neglect to call upon God, are weary of him. The Master tired not the servants with his commands, but they tired him with disobedience. What were the riches of God's mercy toward them? I, even I, am he who yet blotteth out thy transgressions. This encourages us to repent, because there is forgiveness with God, and shows the freeness of Divine mercy. When God forgives, he forgets. It is not for any thing in us, but for his mercies' sake, his promise' sake; especially for his Son's sake. He is pleased to reckon it his honour. Would man justify himself before God? The attempt is desperate: our first father broke the covenant, and we all have copied his example. We have no reason to expect pardon, except we seek it by faith in Christ; and that is always attended by true repentance, and followed by newness of life, by hatred of sin, and love to God. Let us then put him in remembrance of the promises he has made to the penitent, and the satisfaction his Son has made for them. Plead these with him in wrestling for pardon; and declare these things, that thou mayest be justified freely by his grace. This is the only way, and it is a sure way to peace.