He did not need any testimony about man, for He knew what was in a man.
καὶ ὅτι οὐ χρείαν εἶχεν ἵνα τις μαρτυρήσῃ περὶ τοῦ ἀνθρώπου· αὐτὸς γὰρ ἐγίνωσκε τί ἦν ἐν τῷ ἀνθρώπῳ.