In explaining to His puzzled disciples about this form of teaching, with a sad irony that reveals both His heart's yearning and His mental keenness, He uses more than once with variations this famous bit from Isaiah. He makes the truth stand out more sharply by stating the opposite of what He desires, making the contrast between His words and His known desires so strong as not only to make plain the meaning intended, but to give it a sharper emphasis. The result that began with ears and eyes quickly affected the _tongue_. That is nature's path. The inner road from ear and eye is straight to the tongue. The tongue is the index of man's whole being. While through ear and eye he receives all that ever gets in, through the tongue his whole being is revealed. Of course his personality reveals itself very much otherwise. In the carriage of the body. Strikingly so in the look of the eye. The body itself, especially the face, becomes in time the mould of the spirit within. Yet the tongue--what is said, how it is said, what is _not_ said, the tone of voice--the tongue is the index of the spirit. There is no stronger indication of mastery over one's powers than in control of the tongue. When God would break up man's first great ambitious scheme of a self-centred monopoly on the Shinar plains, He simply touched his tongue. The first evidence of God's touch in the re-making of man on that memorable Pentecost day was upon his tongue. The effect upon his tongue of the break with God has been radical and strange. Dumbness, and slowness or thickness of speech alternate with an unnatural sharpness. Sometimes the spittle has a peculiar oiliness that results in a certain slipperiness of statement. Sometimes it has a bitter, poisonous, acid quality that eats its way into the words. There is a queer backward movement in biting sometimes. Withal a strange looseness of speech regarding the holiest things, and the most awesome truths, and the Holy One Himself. The moment a man gets a vision of God he is instantly conscious of something the matter with his tongue. The sight that comes to his eyes, the sound to his ears makes him painfully self-conscious regarding the defect in his tongue. Moses found himself slow-tongued. Isaiah felt the need of the cleansing coal for his tongue. But man's whole inner mental process was affected. A peculiar sense of fear, of dread, is woven inextricably into the very fibre of man's being. His first reported word after that break was, "I was afraid." That sense of fear--a horrid, haunting, nightmare thing--has affected all his thinking and planning and every-day speech. No phrase is oftener on man's tongue than "I'm afraid." Isaiah's classic utterance about ears and eyes has a counterpart equally classic from Paul's pen, about the effect of sin upon man's mental processes. A few lines in the letter to the Ephesian circle of churches give a sort of bill of details of the mental steps down that slope from the Eden gate.