Mukhtasar Bukhari

Ameer-ul-Mu'mineen Umar bin Khattab (may Allah be pleased with him) says that the wealth of Banu Nadir was of the type which Allah granted to His Messenger (peace be upon him) without battle. The Muslims had not made their horses or riders run upon it, meaning there was no occasion of war. So that wealth was taken especially by the Prophet (peace be upon him), and from it he would give his family their expenses for one year. After a year, whatever remained, he would spend it on weapons, horses, and for striving in the path of Allah.