36. Lord, whither goest thou? This question is founded on that saying of Christ,

I said to the Jews, that whither I go you cannot come, so now I say to you,
(John 13:33.)

From this it is evident how ignorant Peter was, who, after having been so frequently warned about Christ’s departure, was as greatly perplexed as if he had heard something new. Yet in this respect we are too like him; for we hear daily from the mouth of Christ all that is fitted for usefulness in life, and all that is necessary to be known, and, when we come to practice, we are as much astonished as apprentices to whom not a word had ever been spoken. Besides, Peter shows that he is under the influence of an immoderate desire of Christ’s bodily presence; for he reckons it absurd that, while he remains, Christ shall go elsewhere.

Whither I go. By these words Christ restrains Peter’s excessive desire. His language is concise, as becomes a Master, but immediately softens the hardness of his statement. He shows that it will only be for a time that he shall be separated from his disciples. We are taught by this passage to subject all our desires to God, that they may not go beyond their proper bounds; and if at any time they become extravagant and foolish, let us at least submit to be held in by this bridle. That we may not lose courage, let us avail ourselves of the consolation which is immediately added, when Christ promises that we shall one day be gathered to him.

But thou shalt follow me afterwards. He means that Peter is not yet ripe for bearing the cross, but, like corn still in the blade, must be formed and strengthened by the progress of time, that he may follow. We ought therefore to pray to God to carry forward to a higher degree of excellence what he has begun in us. In the meantime, we must creep, till we are able to run more swiftly. Now as Christ bears with us, while we are tender and delicate, so let us learn not to reject weak brethren, who are still very far from the goal. It is desirable, indeed, that all should run with the greatest eagerness, and we ought to encourage all to quicken their pace; but if there are any who walk more slowly, we ought to hope well concerning them, provided that they keep the road.

37. Why cannot I follow thee now? By these words Peter declares that he was dissatisfied with Christ’s answer. He is aware that he has been warned of his own weakness, from which he concludes that it is his own fault that hinders him from following Christ immediately; but he is not at all convinced of it, for mankind are naturally puffed up with confidence in their own value. This expression of Peter shows the opinion which we entertain from our very birth, which is, that we attribute more to our own strength than we ought to do. The consequence is, that they who can do nothing venture to attempt every thing, without imploring the assistance of God.

38. Wilt thou lay down thy life for me? Christ did not choose to debate with Peter, but wished that he should grow wise by his own experience, like fools, who never grow wise till they have received a stroke. Peter promises unshaken firmness, and indeed expresses the sincere conviction of his mind; but his confidence is full of rashness, for he does not consider what strength has been given to him. Now since this example belongs to us, let each of us examine his own defects, that he may not be swelled with vain confidence. We cannot indeed make too large promises about the grace of God; but what is here reproved is the arrogant presumption of the flesh, for faith rather produces fear and anxiety.

The cock will not crow. As presumption and rashness proceed from ignorance of ourselves, Peter is blamed for pretending to be a valiant soldier while he is beyond arrow-shot; for he has not yet made trial of his strength, and imagines that he could do any thing. He was afterwards punished, as he deserved, for his arrogance. Let us learn to distrust our own strength, and to betake ourselves early to the Lord, that he may support us by his power.