Sunan an-Nasa'i, Hadith 3444 ⓘ
It was narrated that 'Aishah said: "The Messenger of Allah gave his wives the choice; was that a divorce?"
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا خَالِدٌ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ سُلَيْمَانَ، عَنْ أَبِي الضُّحَى، عَنْ مَسْرُوقٍ، عَنْ عَائِشَةَ، قَالَتْ قَدْ خَيَّرَ رَسُولُ اللَّهِ صلى الله عليه وسلم نِسَاءَهُ أَفَكَانَ طَلاَقًا .
also referenced under: Book 27, Hadith 56 (In-Book) & Volume 4, Book 27, Hadith 3474 (DarusSalam)