To that future our Lord passes, as His last reason for the command and motive for obeying it, in verse 38. One great hindrance to out-and-out discipleship is fear of what the world will say. Hence come compromises and weak compliance on the part of disciples too timid to stand alone, or too sensitive to face a sarcasm and a smile. A wholesome contempt for the world's cackle is needed for following Christ. The geese on the common hiss at the passer-by who goes steadily through the flock. How grave and awful is that irony, if we may call it so, which casts the retribution in the mould of the sin! The judge shall be 'ashamed' of such unworthy disciples--shall blush to own such as His. May we venture to put stress on the fact that He does not say that He will reject them? They who were ashamed of Him were secret and imperfect disciples. Perhaps, though He be ashamed of them, though they have brought Him no credit, He will not wholly turn from them.
How marvellous the transition from the prediction of the Cross to this of the Throne! The Son of Man must suffer many things, and the same Son of Man shall come, attended by hosts of spirits who own Him for their King, and surrounded by the uncreated blaze of the glory of God in which He sits throned as His native abode. We do not know Jesus unless we know Him as the crucified Sacrifice for the world's sins, and as the exalted Judge of the world's deeds.
He adds a weighty word of enigmatical meaning, lest any should think that He was speaking only of some far-off judgment. The destruction of Jerusalem seems to be the event intended, which was, in fact, the beginning of retribution for Israel, and the starting-point of a more conspicuous manifestation of the kingdom of God. It was, therefore, a kind of rehearsal, or picture in little, of that coming and ultimate great day of the Lord, and was meant to be a 'sign' that it should surely come.