Sunan an-Nasa'i, Volume 4, Book 27, Hadith 3472 (DarusSalam) ⓘ
It was narrated that 'Aishah said: "The Messenger of Allah gave his wives the choice but that was not a divorce."
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا خَالِدٌ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ عَاصِمٍ، قَالَ قَالَ الشَّعْبِيُّ عَنْ مَسْرُوقٍ، عَنْ عَائِشَةَ، قَالَتْ قَدْ خَيَّرَ رَسُولُ اللَّهِ صلى الله عليه وسلم نِسَاءَهُ فَلَمْ يَكُنْ طَلاَقًا .
also referenced under: Hadith 3442 (Reference) & Book 27, Hadith 54 (In-Book)