1 Corinthians 1:14
6 “I thank God that I baptized none of you but Crispus and Gaius.” “Why are you elate at having baptized, when I for my part even give thanks that I have not done so!” Thus saying, by a kind of divine art (οἰκονομικῶς) he does away with their swelling pride upon this point; not with the efficacy of the baptism, (God forbid,) but with the folly of those who were puffed up at having been baptizers: first, by showing that the Gift is not theirs; and, secondly, by thanking God therefore. For Baptism truly is a great thing: but its greatness is not the work of the person baptizing, but of Him who is invoked in the Baptism: since to baptize is nothing as regards man's labor, but is much less than preaching the Gospel. Yea, again I say, great indeed is Baptism, and without baptism it is impossible to obtain the kingdom. Still a man of no singular excellence is able to baptize, but to preach the Gospel there is need of great labor.
Source: Homilies on First Corinthians (New Advent)