John Gill Bible Commentary

Then they said unto him, where is he?.... For Christ had withdrawn himself and was gone; whether on account of the Jews, who he knew would be irritated by this miracle, or whether to avoid all popular applause and glory, which he sought not, is not certain; it may be on both accounts: this question, however, was put, not out of good will to Christ, but that they might apprehend him, and bring him before the sanhedrim, for doing work on the sabbath day; and such enmity there is in carnal men, at the conversion of sinners, their acquaintance, instead of rejoicing at it: he said I know not; for when he returned from the pool, Jesus was gone: and so it sometimes is, that when Christ has wrought a good work of grace upon the heart, he withdraws himself for a while, and the converted sinner knows not where he is.