John 8:26-30 I have many things to say and to judge of you: but he that sent me is true; and I speak to the world those things which I have heard of him. They understood not that he spoke to them of the Father. Then said Jesus unto them, When you have lifted up the Son of man, then shall you know that I am he, and that I do nothing of myself; but as my Father has taught me, I speak these things. And he that sent me is with me: the Father hath not left me alone; for I do always those things that please him. As he spoke these words, many believed on him.
While continuing the discourse with the Jews, Jesus said that He had many things to say and to judge them of: but that the Father that sent Him is true; and He spoke to them those things which He has heard of the Father. (John 8:14, 16, 18, 26). The Jews didn’t understand that He spoke to them of the Father.
Jesus explained to them that when they have lifted up (crucified, John 3:14; 12:34) the Son of Man, then by His resurrection and ascension shall they know that He is the light of the world, the Son of God.
He did nothing of Himself; but as His Father taught Him; we learn from Christ’s Union with the Father the following: The Son can do nothing of Himself (John 5:17, 19, 30; 8:18, 28); Christ did not seek His own will, but the will of the Father (John 5:30; 6:38); He didn’t seek His own glory (John 8:50, 54); His doctrine was not His, but the Father that sent Him (John 7:16; 8:26, 38); Christ always did those things that please the Father (John 8:29); He came from God, not of Himself (John 8:42; 16:28); He did not speak of Himself, but the Father commanded Him what to speak (John 10:25, 37-38; 14:10-11).
John 7:32-36 The Pharisees heard that the people murmured such things concerning him; and the Pharisees and the chief priests sent officers to take him. Then said Jesus unto them, Yet a little while am I with you, and then I go unto him that sent me. You shall seek me, and shall not find me: and where I am, thither you cannot come. Then said the Jews among themselves, Whither will he go, that we shall not find him? will he go unto the dispersed among the Gentiles, and teach the Gentiles? What manner of saying is this that he said, You shall seek me, and shall not find me: and where I am, thither you cannot come?
The Pharisees heard that the people murmured about Jesus being the Christ and they and the chief priests sent officers to arrest Him. Jesus responded by giving the nineteenth New Testament prophecy which was fulfilled: that He will be with them only a little longer – He was crucified 7 months later at the next Passover when He becomes the Passover lamb for all men – and then He went back to the Father at the ascension. They shall seek Him, and not find Him was a prophetic reference to the nation seeking a deliverer in vain when the Romans would come and destroy their city in 70 AD.
And where He will be (in Heaven), they cannot come. One must meet certain conditions to go up to where He now is. If one is cut off in his sins he will never be able to go there, but if one is saved from them he will go there at death or after the rapture (2Cor. 5:8; Php. 1:21-24; Heb. 12:23; Rev. 6:9-11).
The Jews thought that Jesus would go someplace else on earth and teach other nations (Gentiles simply means non-Israelites nations). They did not comprehend that He would die for them and return to Heaven.