As they ministered to the Lord - It is probable that this took place on some day set apart for fasting and prayer. The expression “ministered to the Lord” means as they were engaged in prayer to the Lord, or as they were engaged in divine service. The Syriac thus renders the passage.
The Holy Ghost said - Evidently by direct revelation.
Separate me - Set apart to me, or for my service. It does not mean to ordain, but simply to designate, or appoint to this specific work.
For the work whereunto I have called them - Not the apostolic office, for Saul was called to that by the express revelation of Jesus Christ Galatians 1:12, and Barnabas was not an apostle. The “work” to which they were now set apart was that of preaching the gospel in the regions round about Antioch. It was not any permanent office in the church, but was a temporary designation to a missionary enterprise in extending the gospel, especially through Asia Minor, and the adjacent regions. Accordingly, when, in the fulfillment of this appointment, they had traveled through Seleucia, Cyprus, Paphos, Pamphylia, Pisidia, etc., they returned to Antioch, having fulfilled the work to which they were separated. See Acts 14:26-27. “Whereunto I have called them.” This proves that they received their commission to this work directly from God the Holy Spirit. Paul and Barnabas had been influenced by the Spirit to engage in this work, but they were to be sent forth by the concurrence and designation of the church.