When they had fasted and prayed. That they may obey the oracle, they do not only send Paul and Barnabas away; but also with a solemn rite they appoint them to be the apostles of the Gentiles; it is without question that this was a public fast. Luke said before, that they were fasting, forasmuch as they were busied in their ministry: it might be that that was according to the custom; but now there is another reason, for in appointing a public fast, which used to be done in hard matters and of great importance, they provoke both themselves and others unto an earnest ferventness in prayer, for this is oftentimes added in Scripture as a help to prayer; but (it was a matter of such weight to erect the kingdom of Christ amongst the Gentiles) the teachers of Antioch do not without cause earnestly pray the Lord, that he will enable his servants; [1] and that was not the end of their prayer, that God would, by his Spirit of wisdom and discretion, govern their judgments in choosing, because all disputation or doubting concerning this matter was taken away; but that God would furnish those with the Spirit of wisdom and strength whom he had already chosen to himself, that he would strengthen them with his power against all the invasions of Satan and the world, that he would bless their labors, that they might not be unfruitful, that he would open a gate for the new preaching of the gospel. The laying on of hands which Luke reckoneth up, in the third place, was a kind of consecration, as we have said, (Acts 6:6.) For the apostles retained the ceremony which was used amongst the Jews, according to the old custom of the law; as also kneeling, and such rites, which were profitable to exercise godliness. In sum, this is the end why they laid their hands upon Barnabas and Paul, that the Church might offer them to God, and that they might with their consent declare that this office was enjoined them by God; for the calling was properly God's alone, but the external ordaining did belong to the Church, and that according to the heavenly oracle.

Footnotes

1 - "Ut det pares servis suis humeros," that he may make the shoulders of his servants equal to the burden, may fit them for the office.

And when they had fasted - They were fasting when they were commanded to set them apart. Yet this probably refers to an appointed day of prayer, with reference to this very purpose. The first formal mission to the Gentiles was an important event in the church, and they engaged in this appointment with deep solemnity and with humbling themselves before God.
And prayed - This enterprise was a new one. The gospel had been preached to the Jews, to Cornelius, and to the Gentiles at Antioch. But there had been no solemn, public, and concerted plan of sending it to the Gentiles, or of appointing a mission to the pagan. It was a new event, and was full of danger and hardships. The primitive church felt the need of divine direction and aid in the great work. Two missionaries were to be sent forth among strangers, to be exposed to perils by sea and land; and the commencement of the enterprise demanded prayer. The church humbled itself, and this primitive missionary society sought, as all others should do, the divine blessing to attend the labors of those employed in this work. The result showed that the prayer was heard.
And laid their hands on them - That is, those who are mentioned in Acts 13:1. This was not to set them apart to the apostolic office. Saul was chosen by Christ himself, and there is no evidence that any of the apostles were ordained by the imposition of hands (see Acts 1:26 notes; Matthew 10:1-5 notes; Luke 6:12-16 notes), and Barnabas was not an apostle in the original and unique sense of the word. Nor is it meant that this was an ordination to the ministry, to the once of preaching the gospel, for both had been engaged in this before. Saul received his commission directly from the Saviour, and began at once to preach, Acts 9:20; Galatians 1:11-17. Barnabas had preached at Antioch, and was evidently recognized as a preacher by the apostles, Acts 9:27; Acts 11:22-23. It follows, therefore, that this was not an ordination in the doctrinal sense of this term, either Episcopal or Presbyterian, but was a designation to a particular work - a work of vast importance; strictly a missionary appointment by the church, under the authority of the Holy Spirit. The act of laying hands on any person was practiced not only in ordination, but in conferring a favor, and in setting apart for any purpose. See Leviticus 3:2, Leviticus 3:8,Leviticus 3:13; Leviticus 4:4, Leviticus 4:29; Leviticus 16:21; Numbers 8:12; Mark 5:23; Mark 16:18; Matthew 21:46. It means in this case that they appointed them to a particular field of labor, and by laying hands on them they implored the blessing of God to attend them.
They sent them away - The church by its teachers sent them forth under the direction of the Holy Spirit. All missionaries are thus sent by the church; and the church should not forget its ambassadors in their great and perilous work.

And when they had fasted and prayed, and laid their hands on them -
1. They fasted: this was probably done by the whole Church.
2. They prayed, that God would bless and prosper them in their work.
3. They land hands upon them; thus solemnly appointing them to that particular work.
But was it by this fasting, praying, and imposition of hands that these men were qualified for this work? No. God had already called them to it, Acts 13:2, and he who called them had qualified them. Both their call and their qualification came from God; but he chose that they should have also the sanction of that Church of which they had been members; and therefore he said, Separate me, etc. The ordination of elders among the Jews was by three persons; and here we find three, Simeon, Lucius, and Manaen, ordaining two others, Barnabas and Saul. But how did the Jews ordain? Not by imposition of hands: this is strictly forbidden, see Maimon. Sanh. chap. 4. "After what manner is the ordaining of elders for ever? Not that they should lay their hands on the head of an elder; but only that they should call him Rabbi, and say to him, Behold, thou art ordained, and hast power of judging, etc." It is remarkable that the imposition of hands in the ordaining of elders was not used among the ancient Jews, probably never under the first temple; and rarely, if ever, under the second. See Lightfoot on this place. The Church at Antioch, however, did depart from this custom: they put their hands on the heads of Barnabas and Saul; thus designating them to be the persons whom they, under the direction of the Holy Spirit, sent to preach the Gospel of Christ to the heathen.
When the Holy Spirit said, Separate me Barnabas and Saul for the work whereunto I have called them, and the elders of the Church, in consequence, prayed, fasted, and laid their hands upon them, they certainly understood that by acting thus they fulfilled the mind of the Spirit. Hence, is it not evident that, when the elders of the Church of God have good reason to believe that He has called certain persons to the work of the ministry, and qualified them for that work, they should proceed as the elders of the Church of Antioch did; and by fasting, prayer, and imposition of hands, separate those persons for the work whereunto God has called them. Such persons will consider themselves accountable to God and his Church, and should take care how they use the gift and authority received from both. Is it not being wise above what is written to say, "When God has called and given authority, there is no need of ordination or appointment from man?" I would just ask the objector, Why, then, when God had called Barnabas and Saul to the work, did he command the Church to separate them to him for that very work? And why did they, in obedience, fast, pray, and lay hands upon them? I shall dispute with no man about the superior excellence of the episcopal or presbyterian form in ordination: if all the preliminaries be right, they may be both equally good, for all that I have ever been able to learn to the contrary; but that there should be some proper scriptural form attended to, I am fully satisfied. Besides, if the plan of the Church at Antioch were regularly and faithfully followed, in sending forth the ministers of the Gospel, no man can prove that God would not own them in an especial manner, and more particularly prosper their work. But, O ye rulers of the Church! be careful, as ye shall answer it to God, never to lay hands on the head of a man whom ye have not just reason to believe God has called to the work; and whose eye is single, and whose heart is pure. Let none be sent to teach Christianity, who have not experienced it to be the power of God to the salvation of their own souls. If ye do, though they have your authority, they never can have the blessing nor the approbation of God. "I sent them not: therefore they shall not profit this people at all, saith the Lord." Jeremiah 23:32.

(2) And when they had fasted and prayed, and laid [their] hands on them, they sent [them] away.
(2) Fasting and solemn prayers were used before the laying on of hands.

And when they had fasted and prayed,.... Not when they had done fasting and praying, at the time the Holy Ghost made an impulse on their minds, to separate two of their brethren to a work they were appointed to; but at another time, which was fixed for that purpose; when they fasted and prayed, not for direction, who they were to set apart and send; for the persons were before pointed out to them, but that they might have every needful gift and qualification for the work, and be succeeded in it:
and laid their hands on them; not as ordaining them, for this was not an ordination; the Apostle Paul particularly was not ordained an apostle by man, but by Jesus Christ; who personally appeared to him, and made and ordained him his minister and apostle; and much less by men inferior to himself, as Simeon, Lucius, and Manaen were; but this was a gesture and ceremony used among the Jews, when they wished any blessing or happiness to attend any persons; and so these prophets, when they separated Paul and Barnabas from their company, and were parting from them, put their hands on them, and wished them all prosperity and success: could this be thought to be an ordination, as it cannot, since both of them were stated and authorized ministers of the word, and one of them an apostle long before this; there might seem some likeness between it and the Jewish ordination of elders, which was done by three (b), as here were Simeon, Lucius, and Manaen; but then this was not done without the land of Israel, as here, nor by imposition of hands (c): now when they had thus prayed for them, and wished them well, they sent them away; to do the work they were called unto; not in an authoritative way, but in a friendly manner they parted with them, and bid them farewell.
(b) Misn. Sanhedrin, c. 1. sect. 3. (c) Maimon. & Bartenora in ib. & Maimon. Hilchot Sanhedrin, c. 4. sect. 2, 3.

laid their hands on them--(See on Acts 6:6) --"recommending them to the grace of God for the work which they had to fulfil" (Acts 14:26).
sent them away--with the double call--of the Spirit first, and next of the Church. So clothed, their mission is thus described: "They being sent forth by the Holy Ghost." Have we not here for all time the true principle of appointment to sacred offices?

When they had fasted and prayed. This verse shows how they were set apart. It was by fasting, prayer, and the laying on of hands. They were not thus set apart to an order or rank in the kingdom, but to a work unto which they were called. They were not made priests, or bishops, but missionaries. This act did not make Paul an apostle. Christ chose him, as he had Peter, John and the others.
They sent them away. As the missionaries of the church at Antioch to the heathen. We find that they return to report to the church (Acts 14:27) after a long missionary tour.

Then having fasted - Again. Thus they did also, Acts 14:23.