Maalik ibn Aws ibn Hadathan said that he heard Umar ibn Khattab say that the property of Banu Nadir was fai that Allah granted to His Messenger (SAW) because the Muslims did not push their horses or camels for that (there being no fighting for it). So it was exclusively for Allahs Messenger . Hence, he drew from it a year’s allowance for his family and spent the rest on horses, weapons, etc. to prepare for jihad.
[Bukhari 2904, Muslim 1757]