1 Corinthians 9:6

Or I only and Barnabas [Though not one of the twelve, he is called an apostle (Acts 14:14), for he was a messenger or apostle of the Holy Spirit, and of the church at Antioch (Acts 13:2) and was associated with Paul (Galatians 2:9). His name was illustrious enough at Corinth to give countenance to Paul's course. If Barnabas and Paul wrought out their self-support to be nobly independent, did their voluntary sacrifice of rights abolish those rights, or prove that they never existed? This late reference to Barnabas is interesting, for it shows that he was still at work and was still loved of Paul despite their disagreement concerning John Mark. Having thus proved his right to maintenance by the example of other church leaders, Paul now goes on to give an argument in six heads showing that the practice of these leaders was wholly lawful and proper. First argument: Wages for service is the rule in all employment; in proof of this, three instances are cited, the soldier, the vine-dresser, the shepherd], have we not a right to forbear working?