It has been narrated on the authority of'Abdullah bin 'Umar that the Messenger of Allah (ﷺ) used to give (from the spoils of war) to small troops sent on expeditions something more than the due share of each fighter in a large force. And Khums (one-fifth of the total spoils) was to be reserved (for Allah and His Apostle) (ﷺ) in all cases.
Related hadith on this topic
Explanation & Benefits
Shaykh Maulana Abdul Aziz Alvi
Hadith Commentary: Benefits and Issues: From this hadith it is understood that, after extracting the fifth (khums) from the spoils (ghanimah), the voluntary (nafl) is given. First, the fifth portion is separated from the entire spoils, then the khums is given. Whether it is from the share of the warriors (mujahideen) from the original spoils or from the khums, it is given accordingly.
Source: Tuhfat al-Muslim: Commentary on Sahih Muslim, Page: 4565
Shaykh Abdul Sattar al-Hammad
Hadith Commentary:
➊
In the terminology of Islamic law, "nafl" refers to the gift that the Imam gives to a person who has shown some achievement in battle.
➋
From the first hadith, it is understood that it is permissible to give a nafl from the spoils of war in addition to the allotted share, because it is explicitly mentioned that the warriors were given, as a reward, an extra camel each besides their share of the spoils. The Messenger of Allah (sallallahu alayhi wa sallam) did not object to this distribution.
➌
According to the second hadith, some warriors may be given a greater share than others due to their good performance. However, this additional share will be given from the khums (one-fifth portion). (: ‘Umdat al-Qari: 404/10)
➍
The purpose of Imam Bukhari (rahimahullah) is to show that the Imam is authorized to distribute the wealth of khums at his own discretion. He may give more to someone due to their distinguished services. And Allah knows best.
Source: Hidayat al-Qari: Commentary on Sahih Bukhari, Urdu, Page: 3135