The writing may be with invisible ink, but it will be legible one day. It may long lie dormant, as Vesuvius did, till great trees grow on the floor of the crater, but all the while the communication with the central fires is open, and one day they will burst out. So conscience may become seared, though perhaps never so completely as that there are no intervals when it speaks. But at all events the tendency of each sin is in that direction. One does not know how far one may go towards ‘Evil! be thou my good’-or how far towards incapacity of distinguishing evil. It brings on colour-blindness to some extent. It does so partly by sophisticating it-the sensibility to right and wrong being weakened by every evil act, as a cold in the head takes away the sense of smell. It is also written on the stone horns of the altar, with a diamond which can cut the rock All wrong-doing writes indelible records on the conscience. So Judah’s sin is, as it were, eaten into their heart, or, if we might so say, tattooed on it. The ‘red-leaved tablets of the heart’ are like waxen tables on which an iron stylus makes a deep mark, an ineradicable scar. First, on their hearts, which reminds us of the promise of the new covenant to be written on the heart. It describes the sin of the nation as indelible. The first is part of a prophet’s solemn appeal. I have put these verses together because they all deal with substantially the same metaphor. The plural “altars” points probably to the former. 2Corinthians 3:3), and blazoned upon the “horns of the altars” of their false worship, or of the true worship of Jehovah which they had polluted and rendered false. The words describe a note of infamy that could not be erased, and this was stamped in upon the tablets of the heart (comp. 15), and may have been in use in Phœnicia or Palestine. Such instruments were known to the Romans (Pliny, Hist. (For the diamond as a precious stone a different word is used in Exodus 28:18.) Strictly speaking, it was applied only to the diamond-point set in iron used by engravers. With the point of a diamond.-The word expresses the idea of the hardness rather than the brilliancy of the diamond, and is rendered “adamant” in Ezekiel 3:9 Zechariah 7:12. In Psalm 45:1 it seems to have been used of the instrument with which the scribe wrote on his tablets. (1) A pen of iron.- i.e., a stylus, or graving tool, as in Job 19:24, chiefly used for engraving in stone or metal. Ellicott's Commentary for English ReadersXVII.