The parable’s fulfillment is one of the features of that “sign.” The time of its fulfillment is shown in its opening words: “When the Son of man arrives in his glory, and all the angels with him, then he will sit down on his glorious throne.

When a person reasons on this, it becomes evident that Christ’s ‘arrival’ in Kingdom power and glory must occur some time before he brings the Kingdom against this system of things to destroy it and before he begins his thousand-year reign of peace. (Isa. 9:6, 7; Rev. 20:4-6)