14 Now about the midst of the feast Jesus went up into the temple, and taught.
15 And the Jews marvelled, saying, How knoweth this man letters, having never learned?
16 Jesus answered them, and said, My doctrine is not Mine, but His that sent Me.
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.
18 He that speaketh of himself seeketh his own glory: but he that seeketh his glory that sent him, the same is true, and no unrighteousness is in him.
19 Did not Moses give you the law, and yet none of you keepeth the law? Why go ye about to kill Me?
20 The people answered and said, Thou hast a devil: who goeth about to kill thee?
Tabernacles lasted seven days.
Teaching was allowed in the outer court of the Temple, the same place Jesus taught when He was a boy. It was common for different teachers to stand by one of the Temple pillars and teach. We aren’t told what Jesus taught this day. Every seven years, the Law was read at the feast of Tabernacles. This may have been that year.
The crowd marveled at Jesus’ words (v.15), especially since He hadn’t been educated. He replied that He hadn’t been taught by another, nor was He self-taught. What He taught was from the Father (John 12:49).
If any man do His will (v.17) — should be “if any man desires to do His will. Desire = deep-rooted determination
Test 1 (v.17) — If they did the Father’s will, they would have known that what He taught was from the Father.
Test 2 (v.18) — If a man teaches wisdom from himself, he’s just seeking his own glory.
So, to know what Jesus says is really from God, you must determine to yield to God’s will.
He informs us how certainty may be arrived at in connection with the things of God. He tells us how spiritual discernment and assurance are to be obtained. The fundamental condition for obtaining spiritual knowledge is a genuine heart-desire to carry out the revealed will of God in our lives. Wherever the heart is right God gives the capacity to apprehend His truth. — Pink, page 385.