Thou hast forgiven the iniquity of thy people - That is, These calamities came upon them in consequence of their sins, and thou hast dealt with them as if those sins were forgiven. The fact that the tokens of his anger bad passed away, and that his judgments were withdrawn, seemed to prove that their sins had been forgiven. The same form of expression used here - with the same words in Hebrew - occurs in Psalms 32:5. See the notes at that passage. The language suggests the idea of an atonement. Literally, “Thou hast lifted up - or borne - the iniquity of thy people.”
Thou hast covered all their sin - So that it is hidden; and therefore thou dost treat them as if they were righteous, or as if there were no sin. The idea of covering is that expressed in the Hebrew word, which is commonly rendered “atonement” - כפר kâphar - to cover; to cover over; then, to cover over sin; to forgive. The idea suggested in this verse is, that when God withdraws the tokens of his displeasure, we may hope that he has pardoned the sin which was the cause of his anger.