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." (DE)
USC-MSA web (English) reference: Vol. 6, Book 60, Hadith 436 (DE)
Arabic reference (DE): Book 65, Hadith 4914 (DE)