The guide of her youth - Better, the familiar friend (compare Proverbs 16:28; Proverbs 17:9). The “friend” is, of course, the husband, or the man to whom the strange woman first belonged as a recognized concubine. Compare Jeremiah 3:4
The covenant of her God - The sin of the adulteress is not against man only but against the Law of God, against His covenant. The words point to some religious formula of espousals. Compare Malachi 2:14.