Augustine of Hippo

(Serm. 46.) The Gospel therefore is not for sale, that it should be preached for reward. For if they so sell it, they sell a great thing for a small price. Let preachers then receive their necessary support from the people, and from God the reward of their employment. For the people do not give pay to those that minister to them in the love of the Gospel, but as it were a stipend that may support them to enable them to work.