Hadithcore
Sahih al-Bukhari, 5291
sahih

Ibn `Umar added:

"When the period of four months has expired, the husband should be put in prison so that he should divorce his wife, but the divorce does not occur unless the husband himself declares it. This has been mentioned by `Uthman, `Ali, Abu Ad-Darda, `Aisha and twelve other companions of the Prophet (ﷺ) ."

وَقَالَ لِي إِسْمَاعِيلُ حَدَّثَنِي مَالِكٌ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، إِذَا مَضَتْ أَرْبَعَةُ أَشْهُرٍ يُوقَفُ حَتَّى يُطَلِّقَ، وَلاَ يَقَعُ عَلَيْهِ الطَّلاَقُ حَتَّى يُطَلِّقَ‏.‏ وَيُذْكَرُ ذَلِكَ عَنْ عُثْمَانَ وَعَلِيٍّ وَأَبِي الدَّرْدَاءِ وَعَائِشَةَ وَاثْنَىْ عَشَرَ رَجُلاً مِنْ أَصْحَابِ النَّبِيِّ صلى الله عليه وسلم‏.‏

References2 variants
In-Book Reference
Book 68, Hadith 40
USC-MSA web (English) reference
Vol. 7, Book 63, Hadith 213 (deprecated numbering scheme)