Maliks Muwatta Book 36, Hadith Number 40.
Malik related to me from Ibn Shihab from Urwa ibn az-Zubayr that A’isha, the wife of the Prophet, may Allah bless him and grant him peace, said, “Abu Bakr as-Siddiq gave me palm trees whose produce was twenty awsuq from his property at al-Ghaba. When he was dying, he said, ‘By Allah, little daughter, there is no one I would prefer to be wealthy after I die than you. There is no one it is more difficult for me to see poor after I die than you. I gave you palm-trees whose produce is twenty awsuq. Had you cut them and taken possession of them, they would have been yours, but today they are the property of the heirs, and they are your two brothers and your two sisters, so divide it according to the Book of Allah.’ A’isha continued, “I said, ‘My father! By Allah, even if it had been more, I would have left it. There is only Asma. Who is my other sister?” Abu Bakr replied, ‘What is in the womb of Kharija? (Kharija was the wife of Abu Bakr’s ‘brother’ from the Ansar.) I think that it is going to be a girl.'”