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.