The apostle concluded with an exhortation, as he typically did in his epistles. Was Paul boasting when he reviewed his habits of life in Ephesus? I think not. He was reminding these elders of his example that they were to follow as they led the church as he had led them. They were to serve without concern for present material reward. Paul"s policy was not to ask others to support him but to labor at his trade when he or his fellow workers or his converts needed financial support. He did not hesitate to raise money for others, but there are no references in Acts or in his epistles to his having asked for money for himself. I do not believe Paul would object to modern support-raising efforts by Christian workers provided the support raiser was willing to work if his supporters proved unfaithful. Paul emphasized motives ( Acts 20:33) and example ( Acts 20:35). He wanted to give rather than receive and to model that attitude so his converts could see how to demonstrate it in everyday life. [source][source][source]
"The Greco-Roman world was honeycombed by social networks grounded in the priciple of reciprocity, of "giving and receiving." Paul"s exhortation here is to break that cycle and serve and help those who can give nothing in return. This is the practical expression of what being gracious means-freely they had received the good news, and they should freely give with no thought of return." [1][source]
The precise saying of Jesus to which Paul referred here ( Acts 20:35) is not in Scripture. It may have come down to Paul by oral or written tradition, or he may have been summarizing Jesus" teaching (e.g, Luke 6:38). Paul often related his exhortations to Jesus" teachings or example (cf. Romans 12-14; Philippians 2:5-11; 1 Thessalonians 4:1-12). [source][source][source]