Apocalypse Revealed #887
887. 21:6 And He said to me, "It is done!" This symbolically means that it is the Divine truth.
His saying to me means, symbolically, that it is the Divine truth because the Lord said for the third time, "He said to me," and because He said "It is done!" in the present tense. Whatever the Lord says a third time is something to be believed, because it is the Divine truth, and also what He says in the present tense. For three times symbolizes something completed to the end (no. 505), and so, too, when He is about to do something, we are told, "It is done!"