Among the arguments Umar put forward was his statement that the Messenger of Allah ﷺ had three exclusive holdings, Banu Nadir, Khaybar, and Fadak.As for Banu Nadir, it was set aside to meet his emergencies.As for Fadak, it was reserved for travelers in need.As for Khaybar, the Messenger of Allah ﷺ divided it into three portions, two portions distributed among the Muslims, and one portion as maintenance for his family. Whatever exceeded the needs of his family, he distributed among the poor of the Muhajirun.
حدثنا هشام بن عمار حدثنا حاتم بن إسمعيل ح و حدثنا سليمان بن داود المهري أخبرنا ابن وهب أخبرني عبد العزيز بن محمد ح و حدثنا نصر بن علي حدثنا صفوان بن عيسى وهذا لفظ حديثه كلهم عن أسامة بن زيد عن الزهري
كان فيما احتج به عمر رضي الله عنه أنه قال كانت لرسول الله ﷺ ثلاث صفايا بنو النضير وخيبر وفدك فأما بنو النضير فكانت حبسا لنوائبه وأما فدك فكانت حبسا لأبناء السبيل وأما خيبر فجزأها رسول الله ﷺ ثلاثة أجزاء جزأين بين المسلمين وجزءا نفقة لأهله فما فضل عن نفقة أهله جعله بين فقراء المهاجرين
[Its isnad is daif] Bayhaqi narrated it, 7/59, from the hadith of Abu Dawud through him, and the hadith has multiple routes. Zuhri stated explicitly that he heard it in the original hadith, but in this wording he used the ambiguous form "an" (indicating he did not state direct hearing).