The Jews therefore said (were saying one to the other), Will he kill himself, that (because) he saith, Whither I go, thither ye cannot come? This query was one of harsh mockery, and can hardly be exaggerated in malign intent.
The suicide was supposed to have his place in Gehenna, According to Josephus ('Bell. Jud.,' John 3:8. 5), "the darkest regions of Hades would receive the souls of such." The Jews then scoff at his departure as a spontaneous resort to a fate towards which they did rot care or mean to follow him.
Edersheim declares this passage of Josephus not to be sustained by rabbinical authority, and he doubts this aspect of their scorn. He limits it to the Jewish guess that Jesus must be contemplating self.
murder, and as putting deliberately such a distance between them and him that they could not traverse it. The very fact that they had it in their hearts to destroy him makes it probable that they were looking beyond the act of suicide, either to the hell of popular belief or the hatred of contemporaries.
They obviously thought that none but a suicide can determine the time of his departure. Christ proceeded to show them that the reason why his death would separate them from him was a fundamental difference of nature.