Every Muslim is enjoined to go to Mecca, once in the life time, for pilgrimage which becomes obligatory when a man has funds enough for his return journey as well as maintenance of his family and is able to fulfill other conditions laid down for Hajj. This is performed on the 9th of the last month of the Islamic (lunar) month Dhi’l Hajj. .
“Proclaim the Hajj among people so that they come to you on foot and on camels of any kind from deep and distant places”. (22:27)
“The Hajj of the House of Allah (Ka'ba) is obligatory on every one who has the means for the journey to it”. (3:97)
It is incumbent upon everyone to pay wealth-tax on gold, silver, cattle and agricultural produce, when all conditions are fulfilled. This contribution is termed Zakat and should be paid to poor Shia Ithna ‘Asharis having a right to it.
The Quran has commanded the payment of "Zakat" almost as vigorously as the saying of prayers so much so that almost every verse which speaks of saying of prayers speaks of payment of zakat, example:-
“And offer prayers and pay zakat and bow down with those who bow down (in worship)”. (2:43)
Setting aside one-fifth of the amount of a year's savings, (after deducting all the lawful expenses from the earnings of that year) is called Khums. Sadaat (descendants of the Holy Prophet), provided they are Ithna ‘Ashari and poor, will get half of the Khums, while the other half belongs to Imam (A.S.). During the ghaybah of Imam (A.S.), his share must be handed over to the Mujtahid.
The Quranic command for this is as follows:
“And know that out of all wealth that you may acquire, one-fifth of it is for Allah, and for the Messenger and for his kinsmen, and the orphans, the poor and the wayfarer”. (8:41)