Genesis 38:15

15.When Judah saw her. It was a great disgrace to Judah that he hastily desired intercourse with an unknown woman. He was now old; and therefore age alone, even in a lascivious man, ought to have restrained the fervor of intemperance. He sees the woman at a distance, and it is not possible that he should have been captivated by her beauty. (142) The lust kindles him as a stallion neighs when it smells a mare. Hence we gather, that the fear of God, or a regard to justice and prosperity, cannot have flourished greatly in the heart of one who thus eagerly breaks forth to the indulgence of his passions. He is therefore set before us as an example, that we may learn how easily the lust of the flesh would break forth, unless the Lord should restrain it; and thus, conscious of our infirmity, let us desire from the Lord, a spirit of continence and moderation. But lest the same security should steal over us, which caused Judah to precipitate himself into fornication; let us mark, that the dishonor which Judah sustained in consequence of his incest, was a punishment divinely inflicted upon him. Who then will indulge in a crime which he sees, by this dreadful kind of vengeance, to be so very hateful to God?