Albert Barnes Commentary John 12:37

"But though he had done so many signs before them, yet they believed not on him:" — John 12:37 (ASV)

So many miracles. This does not refer to any miracles performed on this occasion, but to all his miracles performed in view of the nation, in healing the sick, opening the eyes of the blind, raising the dead, and so on. John here gives the summary or the result of all his works. Though Jesus had given the most undeniable proof of his being the Messiah, yet the nation did not believe on him.

Before them. Before the Jewish nation. Not in the presence of the people whom he was then addressing, but before the Jewish people.

They believed not. The Jewish nation did not believe as a nation, but rejected him.