Genesis 38:26 - Joseph Benson’s Commentary on the Old and New Testaments

And Judah acknowledged them His guilty conscience and the horror of so foul a fact, together with the sudden surprise, forced him to make an immediate and ingenuous confession. She hath been more righteous than I This he says because he had broken his word with her in withholding Shelah from her, whom he had promised; whereas she had kept her faith with him, and had lived as a widow honestly; besides, she had committed the fact out of desire to have a child, he to satisfy his lust. She was, however, more guilty than he in another respect, as having knowingly committed both adultery and incest, when he designed neither. And he knew her again no more Thus showing the sincerity of his confession, by forsaking the sin confessed, the only sure way of showing it.