Jamieson, Fausset and Brown on Revelation 2:21

21. space--Greek, "time."

of her fornication ... she repented not--The three oldest manuscripts read, "and she willeth not to repent of (literally, 'out of,' that is, so as to come out of) her fornication." Here there is a transition from literal to spiritual fornication, as appears from Re 2:22. The idea arose from Jehovah's covenant relation to the Old Testament Church being regarded as a marriage, any transgression against which was, therefore, harlotry, fornication, or adultery.