Speak tenderly to Jerusalem, and cry unto her, that her warfare is accomplished, that her iniquity is pardoned: for she has received of the LORD'S hand double for all her sins.
Read Chapter 40
Ambrose of Milan
There is also another type of consolation to those who remove heavy punishments, as you have it written in the book of Isaiah: “Comfort, comfort my people,” says the Lord. “Priests, speak to the heart of Jerusalem, comfort it, for its humiliation is complete, its sin is removed, for it has received from the Lord’s hand double for its sins.” Although faith was lacking, punishment makes good; those who are not absolved by the praise of merits are relieved by the removal of punishments. - "Exposition of Psalm 118.18.2"
How is it that some receive at the Lord’s hand double for their sins and the measure of their wickedness is doubly filled up, as in the correction of Israel, while the sins of others are removed by a sevenfold compensation? What is the measure of the Amorites that is not yet full? And how is the sinner either acquitted or chastised again, acquitted perhaps, because reserved for the other world, chastised because healed thereby in this? - "On His Father’s Silence, Oration 16.5"