Sahih Bukhari Volume 4, Book 53, Hadith Number 325.
She used to ask Abu Bakr for her share from the property of Allah’s Apostle which he left at Khaibar, and Fadak, and his property at Medina (devoted for charity). Abu Bakr refused to give her that property and said, “I will not leave anything Allah’s Apostle used to do, because I am afraid that if I left something from the Prophet’s tradition, then I would go astray.” (Later on) Umar gave the Prophet’s property (of Sadaqa) at Medina to ‘Ali and ‘Abbas, but he withheld the properties of Khaibar and Fadak in his custody and said, “These two properties are the Sadaqa which Allah’s Apostle used to use for his expenditures and urgent needs. Now their management is to be entrusted to the ruler.” (Az-Zuhrl said, “They have been managed in this way till today.”)