Sahih al-Bukhari, Book 65, Hadith 4914 (In-Book) ⓘ
Narrated Ibn `Abbas: I intended to ask `Umar so I said, "Who were those two ladies who tried to back each other against the Prophet?" I hardly finished my speech when he said, They were `Aisha and Hafsa."
حَدَّثَنَا عَلِيٌّ، حَدَّثَنَا سُفْيَانُ، حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، قَالَ سَمِعْتُ عُبَيْدَ بْنَ حُنَيْنٍ، قَالَ سَمِعْتُ ابْنَ عَبَّاسٍ ـ رضى الله عنهما ـ يَقُولُ أَرَدْتُ أَنْ أَسْأَلَ عُمَرَ فَقُلْتُ يَا أَمِيرَ الْمُؤْمِنِينَ مَنِ الْمَرْأَتَانِ اللَّتَانِ تَظَاهَرَتَا عَلَى رَسُولِ اللَّهِ صلى الله عليه وسلم فَمَا أَتْمَمْتُ كَلاَمِي حَتَّى قَالَ عَائِشَةُ وَحَفْصَةُ.
also referenced under: Hadith 4914 (DarusSalam) & Volume 6, Book 60, Hadith 436 (USC-MSA)