Narrated Ibn `Abbas:
I intended to ask `Umar about those two ladies who back each other against 'Allah's Messenger (ﷺ) . For one year I was seeking the opportunity to ask this question, but in vain, until once when I accompanied him for Hajj. While we were in Zahran, `Umar went to answer the call of nature and told me to follow him with some water for ablution. So I followed him with a container of water and started pouring water for him. I found it a good opportunity to ask him, so I said, "O chief of the Believers! Who were those two ladies who had backed each other (against the Prophet)?" Before I could complete my question, he replied, "They were `Aisha and Hafsa."
USC-MSA web (English) reference: Vol. 6, Book 60, Hadith 437
Arabic reference: Book 65, Hadith 4915