Albert Barnes Commentary Psalms 103:12

"As far as the east is from the west, So far hath he removed our transgressions from us." — Psalms 103:12 (ASV)

As far as the east is from the west - As far as possible; as far as we can imagine. These are the points in our understanding most distant from each other, and as we can conceive nothing beyond them, so the meaning is that we cannot imagine our sins could be more effectively removed than they are. The literal meaning of the Hebrew is, “like the distance of the east from the west” or, “like its being far.”

So far has he removed our transgressions from us - That is, he has put them entirely away. They are so removed that they cannot affect us anymore. We are safe from all condemnation for our sins, as if they had not been committed at all. Compare the notes at Isaiah 43:25; notes at Isaiah 44:22.