Which was preached (to euaggelisthen). Play on the word euaggelion by first aorist passive participle of euaggelizō, “the gospel which was gospelized by me.”
It is not after man (ouk estin kata anthrōpon). Not after a human standard and so he does not try to conform to the human ideal. Paul alone (1Co 3:3; 1Co 9:8; 1Co 15:32; Rom 3:15) in the N.T. uses this old and common idiom.