John 7:17

ἐάν τις θέλῃ τὸ θέλημα αὐτοῦ ποιεῖν γνώσεται περὶ τῆς διδαχῆς πότερον ἐκ τοῦ Θεοῦ ἐστιν ἢ ἐγὼ ἀπ ἐμαυτοῦ λαλῶ