Narrated Amr ibn Abasah: The Messenger of Allah ﷺ led us in prayer facing a camel which had been taken in booty, and when he had given the salutation, he took a hair from the camel's side and said: I have no right as much as this of your booty, but only to the fifth. and the fifth is returned to you.
Explanation & Benefits
Shaykh Umar Farooq Saeedi
Benefits and Issues:
The Messenger of Allah (sallallahu alayhi wa sallam) would only take one-fifth (khums) from the spoils of war (ghanimah).
In this way, the leader of the Muslims (imam al-muslimin) should also follow the example of the Noble Prophet (sallallahu alayhi wa sallam) in this matter.
And he should not designate any particular item exclusively for himself,
except if there is a specific benefit (maslahah) in doing so.
(Nayl al-Awtar, Kitab al-Jihad, Chapter: That Four Fifths of the Spoils Belong to the Warriors... 7/296; and Chapter: Explanation of al-Safiyy... 7/316)
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 2755