John 8:27

They knew not, &c. For Jesus spake covertly and obscurely, for fear of exciting the hatred of the Pharisees. But some of the more acute of them began to suspect the true meaning of His words, though they did not clearly understand them, and could not refute Him. None of them fully knew it. And God so ordered it, that the Passion of Christ, and the consequent redemption of the world, might not be hindered. (See 1 Cor. ii. 8.) "I withhold the knowledge of Myself," says S. Augustine, "that My Passion may be effected" by your hands.