“If I bear witness
Is not true.”
Ἐὰν ἐγὼ μαρτυρῶ περὶ ἐμαυτοῦ, ἡ μαρτυρία μου οὐκ ἔστιν ἀληθής·
John uniquely indicated that Jesus continued with his theological monologue, using the first person singular. Jesus explained that if he was bearing witness (Ἐὰν ἐγὼ μαρτυρῶ) about himself (περὶ ἐμαυτοῦ), his testimony (ἡ μαρτυρία μου) would not be true (οὐκ ἔστιν ἀληθής). It would not be able to stand. Jesus accepted the Jewish Mosaic Law that you had to have two or more witnesses to sustain a charge in court. By himself, his own testimony would be weak. Are you the only one who brags about yourself?