For example...
For example, when the Prophet sent `Amr bin Hazm to Yemen, he wrote instructions for him in which, among other things, he says, “...to gather the khums of Allāh from the gains [of Yemenis].”[^3] And when the tribe of Bani Kilāl of Yemen sent its khums to the Prophet, the latter acknowledged it by saying, “Your messenger has returned and you have paid the khums of Allāh from the gains (al-ghanā'im).”[^4] It is interesting to note that the Bani Kilāl obeyed the Prophet's order and sent the khums of its gains to him while no war had taken place between the Muslims of Yemen and the unbelievers.
This is a clear indication that khums was not restricted by the Prophet to the spoils of war. The importance given by the Prophet to the issue of khums can also be seen in his advice to the delegation of Bani `Abdu 'l-Qays. It seems that Bani `Abdu 'l-Qays (which was a branch of Rabi`ah) was not a very strong tribe. Moreover, in order to travel to Medina, they had to cross an area inhabited by the Muzar tribe which was against the Muslims.
Consequently, the Bani `Abdu 'l-Qays could not travel safely to Medina except during the months in which warfare was forbidden according to the Arab custom. Once a delegation from Bani `Abdu 'l-Qays came to Medina and said to the Prophet, “We cannot come to you except in the harām months [when warfare is forbidden], and there are between us and you the unbelievers of Muzar.
Therefore, please give us some advice that we may give to those whom we have left behind and that we may enter the Paradise [by acting on it ourselves].” The Prophet advised them to believe in One God, establish prayer, pay zakāt, fast in the month of Ramadhān, and “to pay khums (one-fifth) of whatever you gain.”[^5] The circumstances of the Bani `Abdu 'l-Qays —they were weak and small in number, and were thus prevented from travelling safely to Medina— leaves no room for interpreting the application of khums in the above hadith on spoils of war exclusively.
* * * This lesson is entirely based on Khums: An Islamic Tax (Third Edition, 1992) of Sayyid M. Rizvi Question Paper on Lesson 32 Question 1: [10 points] True or False: (a) Khums means 2.5%. (b) Allah, subhānahu wa ta`ala, talks about khums in verse 8:41. (c) All Sunni sects confine khums to the spoils of war. (d) The first khums was paid by Abu Tālib. (e) Khums is wājib on seven items. Question 2: [20 points] There are differences among the Muslim sects on the items on which khums becomes wājib.