John Gill Commentary John 7:34

"Ye shall seek me, and shall not find me: and where I am, ye cannot come." — John 7:34 (ASV)

You shall seek me
That is, the Messiah, who he was; meaning, that after his departure they should be in great distress, and be very much on the inquiry after, and solicitous for the coming of the Messiah, to be a Redeemer and Deliverer of them out of their troubles:

and shall not find [me] ;
no Messiah will appear, no Saviour will be sent, no Redeemer will come to relieve them; they shall inquire, and look for one in vain, as they did.

And where I am, [thither] you cannot come ;
intimating hereby, that not only their temporal estate and condition would be very distressed and miserable, but also their eternal estate; since they should not be able to come where he would be in his human nature, and where he now was as a divine person, namely, in heaven.