Sahih Muslim , Book 56, Hadith 16 (In-Book) ⓘ

'A'isha said in connection with these words of Allah, the Exalted and Glorious: " And if a woman has reason to fear ill-treatment from her husband or that he might turn away from her" that it was revealed in case of a woman who lived with a person and perhaps he does not want to prolong (his relationship with her) whereas she has had sexual relationship with him (and as a result thereof) she got a child from him and she does not like that she should be divorced, so she says to him: I permit you to live with the other wife.

حَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا أَبُو أُسَامَةَ، حَدَّثَنَا هِشَامٌ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، فِي قَوْلِهِ عَزَّ وَجَلَّ ‏{‏ وَإِنِ امْرَأَةٌ خَافَتْ مِنْ بَعْلِهَا نُشُوزًا أَوْ إِعْرَاضًا‏}‏ قَالَتْ نَزَلَتْ فِي الْمَرْأَةِ تَكُونُ عِنْدَ الرَّجُلِ فَلَعَلَّهُ أَنْ لاَ يَسْتَكْثِرَ مِنْهَا وَتَكُونُ لَهَا صُحْبَةٌ وَوَلَدٌ فَتَكْرَهُ أَنْ يُفَارِقَهَا فَتَقُولُ لَهُ أَنْتَ فِي حِلٍّ مِنْ شَأْنِي ‏.‏