Then: as with the first sentence of many of the chapters in Revelation, the writer indicates that the events that he is seeing in the present chapter follow immediately after events in the previous chapter. In many languages it will be helpful to tie this verse in with what happened in 19.19-21 and say, for example, “After the Messiah conquered the beast, the false prophet, and their soldiers, I saw….”

An angel coming down from heaven: as in 18.1 and elsewhere.

Holding in his hand: if necessary the translation can say “in his right hand.” There is no verb in Greek, which says only “in his hand.”

The key of the bottomless pit: see 9.1; 17.8.

A great chain: this may be said “a heavy chain,” “a thick chain.” It is assumed to be made of metal. In cultures where metal chains are unknown, one may say something like “a big (or, thick) rope,” or else employ some other material that is used for tying up people.

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 .