Albert Barnes Commentary John 7:18

"He that speaketh from himself seeketh his own glory: but he that seeketh the glory of him that sent him, the same is true, and no unrighteousness is in him." — John 7:18 (ASV)

That speaketh of himself. This does not mean about or concerning himself, but refers to one who speaks by his own authority, without being sent by God, as mere human teachers do.

Seeketh his own glory. His own praise, or seeks for reputation and applause. This is the case with mere human teachers; and as Jesus in his discourses manifestly sought to honor God, they should have supposed that he was sent by him.

No unrighteousness. This word here evidently means there is no falsehood, no deception in him. He is not an impostor. It is used in the same sense in 2 Thessalonians 2:10–12. It is true that there was no unrighteousness, no sin, in Jesus Christ, but that is not the truth taught here. It is that he was not an impostor, and the evidence of this was that he did not seek his own glory, but the honor of God. This evidence was furnished in the following ways:

1. In his retiring, unobtrusive disposition; in his not seeking the applause of men.
2. In his teaching such doctrines as tended to exalt God and humble man.
3. In his ascribing all glory and praise to God.