Her sins are heaped high as heaven: the Greek verb translated heaped means “to glue,” that is, to stick to something (see Luke 10.11, where the dust sticks to the feet); here the picture is of sins that stick to one another and keep piling up, until the pile reaches the sky. This is a vivid way of describing the large number of the sins of Babylon (see Jer 51.9). It is possible that here “sky” is more appropriate (so An American Translation, Translator’s New Testament, New Jerusalem Bible, New American Bible, Revised); but heaven may be better, since it leads naturally to the next line. The sins have attracted God’s notice.

God has remembered her iniquities: for this sense of remembered see 16.19; God is going to take action and punish Babylon for her sins. The noun translated iniquities occurs here and translated “wrongdoings” in Acts 18.14; 24.20, and nowhere else in the New Testament. It is related to the verb “to harm,” “to do wrong” (see its use in 11.5; “do evil,” 22.11). This sentence may also be expressed as “God has not forgotten (or, does not take his attention away from) the evil (or, harmful) things Babylon has done.”

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on The Revelation to John. (UBS Handbook Series). New York: UBS, 1993. For this and other handbooks for translators see here .