NET
17 If anyone wants to do God’s will, he will know about my teaching, whether it is from God or whether I speak from my own authority.
Darby
17 If any one desire to practise his will, he shall know concerning the doctrine, whether it is of God, or [that] I speak from myself.
KJV
17 “If any man will do his will, he shall know of the doctrine, whether it be of God, or” [whether] “I speak of myself.”