Charles H. Spurgeon on Psalms 137:8

Who art to be destroyed. hdwdvh has been explained in a variety of ways. Seventy: h talaipwrov; Vulg. misera: others, destroyer, powerful, violent, or fierce. Perhaps it best suits the context to regard it as expressing what is already accomplished: it is so certain, in the view of the Psalmist, that the ruin will come, that he uses the past participle, as if the work were now completed. "O daughter of Babylon, the destroyed!" —"Bibliotheca Sacra and Theological Review."