A question is commonly asked about this fishing of the disciples. Why did Peter and the sons of Zebedee return to what they had been doing before the Lord called them? They were indeed fishermen when He said to them: "Follow Me, and I will make you fishers of men" (Mt 4:19).
Then, of course, they followed Him, so that by leaving everything they fulfilled His command. Thus, when the rich man to whom He said, "Go, sell what you have and give to the poor, and you will have treasure in heaven; and come, follow Me" (Mt 19:21), went away sorrowing, Peter said to Him: "Behold, we have left everything and followed You" (Mt 19:27).
What then does it mean that now, as though abandoning their apostleship, they became what they had been before? They took back what they had left, as if forgetting what they once heard: "No one who puts his hand to the plow and looks back is fit for the Kingdom of Heaven" (Lk 9:62).
If they had done this when Jesus lay buried, before He rose from the dead, we would think they did it because despair had seized their souls. Yet they certainly could not have done so then. The day on which He was crucified held them all in strain until His burial, which took place before evening.
The next day was the Sabbath, when those who observed the custom of the fathers were not permitted to work. On the third day the Lord rose and again called them to hope in Him, which they had already begun to lose. Still, if they had done it then, we would have thought they acted from despair.
But now He had risen alive from the tomb. The truth of His flesh's restoration had been most clearly revealed to their eyes and hands, so that it could be not only seen but touched and even handled. The marks of the wounds had been made available for contemplation. This brought the Apostle Thomas to confession, though he had said before that otherwise he would not believe in His resurrection.
The Holy Spirit had been received through His breathing. From His mouth these words had poured into their ears: "As the Father has sent Me, so I send you. Whose sins you forgive, they are forgiven; whose sins you retain, they are retained" (Jn 20:21, 23). Yet suddenly they became, as before, fishers of fish and not of men.
Those troubled by this question must be answered in this way. Those apostles were not forbidden to procure necessary food by their trade, which was lawful and permitted, if they had no other means of support, while preserving their apostleship unharmed.
Would anyone dare to think or say that the Apostle Paul did not attain the perfection of those who, leaving everything, followed Christ, because he obtained food for himself with his hands so as not to burden any of those to whom he preached the Gospel (cf. 2 Thess 3:7)? Rather, in this was fulfilled what he said: "I labored more abundantly than they all," and he added, "yet not I, but the grace of God which was with me" (1 Cor 15:10).
By this he showed that it must be ascribed to the grace of God that he could labor more than all those apostles in both soul and body. He tirelessly preached the Gospel and yet did not sustain his life from the Gospel as they did, though he sowed the Gospel much more widely and abundantly among many nations where the name of Christ had not previously been preached.
By this he showed that no necessity was imposed on the apostles, but authority was given to live, that is, to receive support, by the Gospel. The same apostle mentions this authority, saying: "If we have sown spiritual things among you, is it too much if we reap your material things? If others share this authority over you, do not we even more? Nevertheless we have not used this authority" (1 Cor 9:11-12).
A little later he said: "Those who serve at the altar share in the offerings of the altar. In the same way the Lord commanded that those who preach the Gospel should live from the Gospel. But I have used none of these things" (1 Cor 9:13-15).
It is therefore quite evident that the apostles were not commanded, but were given authority, to live only from the Gospel. From those in whom they sowed spiritual things by preaching the Gospel, they could reap material things, that is, strengthen the body. As soldiers of Christ, they could receive the due stipend, as it were, from Christ's subjects.
For this reason that same brilliant soldier said shortly before: "What soldier ever serves at his own expense?" (1 Cor 9:7). Yet he himself did not do this, acknowledging that he had labored more than them all.
If blessed Paul, so as not to use with the other preachers of the Gospel the authority that he certainly had equally with them, served at his own expense, then he did this so that his teaching, as though offered for sale, would not offend Gentiles wholly foreign to the name of Christ. Though trained in something else, he learned a craft he had not known before, so that, as a teacher, he might obtain food by his own hands and burden none of his hearers.
How much more natural, then, was the action of blessed Peter, who was already a fisherman and did what he knew how to do, since at that time he had found no other means of support.
But someone will answer: "Why did he not find these means, when the Lord promised, saying: 'Seek first the Kingdom of God and His righteousness, and all these things shall be added to you'" (Mt 6:33)? Certainly, the Lord fulfilled what He promised in this way. For who else brought the fish so that they might be caught?
We must think that He cast them into the need that compelled them to go fishing only because He wished to manifest a miracle. He intended at the same time to feed the preachers of His Gospel and to endow the Gospel itself with so great a mystery, which He meant to indicate through the number of fish. We also must now speak of this, insofar as He Himself grants the ability.
This is a great mystery in the great Gospel of John. So that it might resound with greater force, it was recorded in the last chapter. Thus seven disciples were present at this fishing: Peter, Thomas, Nathanael, the two sons of Zebedee, and two others whose names are passed over in silence. The sevenfold number of disciples points to the end of time. For all times pass within seven days.