I am thankful that I baptized none of you except Crispus and Ga′ius;
εὐχαριστῶ [τῷ θεῷ] ὅτι οὐδένα ὑμῶν ἐβάπτισα εἰ μὴ Κρίσπον καὶ Γάϊον,
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.
Haydock Catholic Bible Commentary: 1 Corinthians
I give God thanks that I baptized none of you, but, &c. It is strange that Quakers should from hence pretend, that S. Paul condemned baptism, when he only tells them, he is glad they were baptized by some other, rather than by him, lest they should say, they were baptized in his name, or think that baptism had a greater virtue, when given by a minister of greater sanctity; whereas it is Christ only, who is the chief minister, who gives grace in baptism, and in the other sacraments. This makes him say, was Paul crucified for you, &c. He tells them the occasion why he baptized few, because he was sent chiefly to preach and to be their apostle, whereas other inferior ministers were employed in baptizing. Wi.