For her sins have reached unto heaven - So in Jeremiah 51:9, speaking of Babylon, it is said, “For her judgment reacheth unto heaven, and is lifted up even to the skies.” The meaning is not that the sins of this mystical Babylon were like a mass or pile so high as to reach to heaven, but that it had become so prominent as to attract the attention of God. Compare Genesis 4:10, “The voice of thy brother’s blood crieth unto me from the ground.” See also Genesis 18:20.
And God hath remembered her iniquities - He had seemed to forget them, or not to notice them, but now he acted as if they had come to his recollection. See the notes on Revelation 16:19.