The verse says...
“And know that whatever thing you gain (of booties), a fifth of it is for Allah and for the Messenger and for the near relatives (Ahlul-Bayt) and the orphans, and the needy and the way-farer, if you believe in Allah and what We sent down to Our servant on the day of distinction (of right from wrong), the day when the two hosts encountered (the day of Battle of Badr), and surely Allah is All-powerful over everything.”*** According to some Islamic traditions that the Shi'ite believe, the meaning of the term /qanimat/ (booty) is not confined to the war spoils, but, besides that, it encompasses my kind of gain which is obtained from mains, diving, trade, and so on.
Thus, the revelation of the verse concerning the battle of Badr is not evidence that its purpose is only ‘war spoils’. Through the first verse of this Surah, the Qur’an allocated all ‘Anfal (the things gained) to Allah and the Messenger, while this verse says that ‘a fifth of it is for Allah and for the Messenger (Ahlul-Bayt)’.
If the objective meaning of the term /qanimat/ (booty) is only ‘the spoils of war’, it must be said that this verse refers to only one instance of Khums (one fifth) and other instances are discussed in some Islamic traditions.
As many traditions of the Shi'ite and also some traditions of the Sunnite indicate, the meaning of the Qur'anic term /oil qurba/ (near relatives) does not envelop all the relatives of the Prophet (S) but its purpose is the immaculate Imams (as) from Ahl-ul-Bayt who possess the rank of leadership. So, the amount of Khoms (one fifth levy) belongs to the divine leader and the Islamic government, not to all the relatives of the Prophet (S).
Other usages of Khoms (one fifth levy) are for indigents, way-farers who are progenies of Bani-Hashim -since it is unlawful to give them alms, and their needs should be provided through Khoms.