In http://ref.ly/Jn7.10, Jesus is cautious about going up to the feast. He travels undetected, and keeps a low profile. He probably travels on the back roads. He does not want Himself to be seen until the set time.
When Jesus told them to go up to the feast, He remained behind in Galilee. The conflict over Christ begins in John 7:11-13. When the Jews saw Jesus’ brethern, they were asked where Jesus was. At the same time, the people began to murmur and debate the character of Jesus. They debated on whether He was a good man or a deceiver. This debate continues today. Deception at that time would result in stoning if found guilty. No one spoke openly on behalf of Jesus for fear of the Jews. Fear can stifle our witness for Christ.
When the feast was midway completed, Jesus is found in the temple teaching. Naturally, Jesus speaks with power and authority. Those who heard Him ask the question concerning His knowledge of the scriptures. They know He has never gone to any schools of learning for the Jews. Character and doctrine go together. A person’s belief affects their behavior. Jesus says that what He teaches comes from the Father who sent Him. If any man does the will of the Father, that individual will know the doctrine of Him. Doing God’s will gives discernment about Christ’s doctrines. The phrase “do His will” in the Greek can also read “desire His will.” The idea behind the words “do” or “desire” mean “to seize with the mind; to be resolved; to have a deeply rooted desire to know and be in God’s will.” [Mattoon’s Treasures, Treasures from John Volume 1 – Chapter 30. The wait for an Opportune Time, p. 217]
The hearer will know what is being taught is of the Father or not. The religious leaders were responsible for teaching the Scriptures. Once again, they are shown their shortcoming concerning their knowledge of the Scriptures. They were caught up in doing their will and teaching the commandments of God according to their tradition. Notice in verse 18 where Jesus bears this out. He that does this is seeking his own glory. They presented themselves as being knowledgeable concerning the scriptures, which caused them to be highly esteemed in the eyes of those they taught. The one that teaches the Scriptures according to the Father is righteous. This individual does not seek accolades from humanity. This individual seeks to glorify God by being a faithful and loyal believer.