Having given a proof of his future glory, Christ reminds his disciples of what he must suffer, that they also may be prepared to bear the cross; for the time was at hand when they must enter into the contest, to which he knew them to be altogether unequal, if they had not been fortified by fresh courage. And first of all, it was necessary to inform them that Christ must commence his reign, not with gaudy display, not with the magnificence of riches, not with the loud applause of the world, but with an ignominious death. But nothing was harder than to rise superior to such an offense; particularly if we consider the opinion which they firmly entertained respecting their Master; for they imagined that he would procure for them earthly happiness. This unfounded expectation held them in suspense, and they eagerly looked forward to the hour when Christ would suddenly reveal the glory of his reign. So far were they from having ever adverted to the ignominy of the cross, that they considered it to be utterly unsuitable that he should be placed in any circumstances from which he did not receive honor. To them it was a distressing occurrence that he should be rejected by the elders and the scribes, who held the government of the Church; and hence we may readily conclude that this admonition was highly necessary. But as the bare mention of the cross must, of necessity, have occasioned heavy distress to their weak minds, he presently heals the wound by saying, that on the third day he will rise again from the dead. And certainly, as there is nothing to be seen in the cross but the weakness of the flesh, till we come to his resurrection, in which the power of the Spirit shines brightly, our faith will find no encouragement or support. In like manner, all ministers of the Word, who desire that their preaching may be profitable, ought to be exceedingly careful that the glory of his resurrection should be always exhibited by them in connection with the ignominy of his death. But we naturally wonder why Christ refuses to accept as witnesses the Apostles, whom he had already appointed to that office; for why were they sent but to be the heralds of that redemption which depended on the coming of Christ? The answer is not difficult, if we keep in mind the explanations which I have given on this subject: first, that they were not appointed teachers for the purpose of bearing full and certain testimony to Christ, but only to procure disciples for their Master; that is, to induce those who were too much the victims of sloth to become teachable and attentive; and; secondly, that their commission was temporary, for it ended when Christ himself began to preach. As the time of his death was now at hand, and as they were not yet fully prepared to testify their faith, but, on the contrary, were so weak in faith, that their confession of it would have exposed them to ridicule, the Lord enjoins them to remain silent till others shall have acknowledged him to be the conqueror of death, and till he shall have endued them with increased firmness.

And he strictly charged them, and commanded them,.... Though he highly approved of this their confession, and pronounced Peter blessed upon it; and signified that it was a discovery which flesh and blood could not make, but what was made to him his Father: yet he gave them a strict charge, and laid his commands on them,
to tell no man that thing; that he was the Messiah, and the eternal Son of God, and the true God, as well as the son of man, and really man: the reasons for this: See Gill on Matthew 16:20.