Luke 9:3

Wishing then that they should be free from the desire of wealth and the anxieties of life, He gave this injunction. He took it as a proof of their faith and courage, that when it was commanded them to lead a life of extreme poverty, they would not escape from what was ordered. For it was fitting that they should make a kind of bargain, receiving these saving virtues to recompense them for obedience to commands. And when He was making them soldiers of God, He girds them for battle against their enemies, by telling them to embrace poverty. For no soldier of God entangles himself in the affairs of a secular life. (2 Tim. 2:4.)

(Orat. ii. 69.) Now in sending His disciples to preach, our Lord enjoined many things on them, the chief of which are, that they should be so virtuous, so constant, so temperate, and, to speak briefly, so heavenly, that no less through their manner of living than their words, the teaching of the Gospel might be spread abroad. And therefore were they sent with lack of money, and staves, and a single garment; He accordingly adds, And he said to them, Take nothing in the way, neither staves.

Of what kind then he ought to be who preaches the Gospel of the kingdom of God is marked out by these Gospel precepts; that is, he must not require the supports of secular aid; and clinging wholly to faith, he must believe that the less he requires those things, the more they will be supplied to him. To those also who wish it, this place admits of being explained, so as to seem only to represent a spiritual temper of mind, which appears to have cast off as it were a certain covering of the body; not only rejecting power and despising wealth, but renouncing also the delights of the flesh itself.

(de Con. l. 2. c. 30.) Or, the Lord did not wish the disciples to possess and carry with them these things, not that they were not necessary to the support of this life, but because He sent them thus to show that these things were due to them from those believers to whom they announced the Gospel, that so they might neither possess security, nor carry about with them the necessaries of this life, either great or little. He has therefore, according to Mark, excluded all except a staff, showing that the faithful owe every thing to their ministers who require no superfluities. But this permission of the staff He has mentioned by name, when He says, They should take nothing in the way, but a staff only.

For He sends them out as very beggars, so that He would have them neither carry bread, nor any thing else of which men are generally in want. Some also understand by the Apostles not carrying scrip, nor staff, nor two coats, that they must not lay up treasures, (which a scrip implies, collecting many things,) nor be angry and of a quarrelsome spirit, (which the staff signifies,) nor be false and of a double heart, (which is meant by the two coats.)