Chapter 32 — Part III: The Decalogue — The Ninth and Tenth Commandments
Section 30. And if to covet the wedded wife of another is entirely unlawful, it is on no account right to desire in- marriage the virgin who is consecrated to religion and to the service of God. But should anyone desire in marriage a married woman whom he thinks to be single, and whom he would not wish to marry if he knew she had a husband living, certainly he does not violate this Commandment. Pharaoh and Abimelech, as the Scripture informs us, were betrayed into this error; they wished to marry Sarah, supposing her to be unmarried, and to be the sister, not the wife of Abraham.