It is narrated from Sayyiduna Malik bin Aws (may Allah be pleased with him) that when Sayyiduna Umar (may Allah be pleased with him) gave his judgement, he said: The Messenger of Allah (peace and blessings be upon him) had three kinds of properties: the property of Banu al-Nadir, Khaybar and Fadak. The property of Banu al-Nadir was for use in emergencies, the property of Fadak was for travellers, and the property of Khaybar he divided into three parts: two parts for the Muslims and the third part for the expenses of his family; if anything was left over from their needs, he would distribute it among the poor Muslims.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13370