The Quran

ضَرَبَ اللَّهُ مَثَلًا لِلَّذينَ كَفَرُوا امرَأَتَ نوحٍ وَامرَأَتَ لوطٍ ۖ كانَتا تَحتَ عَبدَينِ مِن عِبادِنا صالِحَينِ فَخانَتاهُما فَلَم يُغنِيا عَنهُما مِنَ اللَّهِ شَيئًا وَقيلَ ادخُلَا النّارَ مَعَ الدّاخِلينَ

Muhammad Asad

For those who are bent on denying the truth God has propounded a parable in [the stories of] Noah's wife and Lot's wife: they were wedded to two of Our righteous servants, and each one betrayed her husband;¹ and neither of the two [husbands] will be of any avail to these two women when they are told [on Judgment Day], "Enter the fire with all those [other sinners] who enter it!"²

Lit., "and both betrayed them", i.e., their respective husbands. The story of Lot's wife and her spiritual betrayal of her husband is mentioned in the Qur'an in several places; see, in particular, note 66 on 7:83 and note 113 on 11:81. As regards Noah's wife, the above is the only explicit reference to her having betrayed her husband; it would seem, however, that the qualification of "those on whom [God's] sentence has already been passed" in 11:40 applies to her no less than to her son (whose story appears in 11:42-47).
The "parable" (mathal) of these two women implies, firstly, that even the most intimate relationship with a truly righteous person - even though he be a prophet - cannot save an unrepentant sinner from the consequences of his sin; and, secondly, that a true believer must cut himself off from any association with "those who are bent on denying the truth" even if they happen to be those nearest and dearest to him (cf. 11:46).