A highly recommended and favored kind of worship is donation that is given in the sake of Allah. Since donations are optional, not mandatory, they are used to serve the general needs of Islam and Muslims.
The Holy Prophet (S) said: “My community will continue to live fairly while they are faithful (to each other), return the deposits (to their owners), and give alms (of their property); but, if they do not fulfil these duties, they will encounter famine and scarcity.”
Wasa’il-ush Shia’ah, vol. 6, p.13
Imam Amir-ul-Mu’mineen ‘Ali (‘a) said: “O’ children of Adam! Be your own representative in the matter of your property and do with it whatever you like to be done with it after your death.”
Note: The meaning is that if a person desires that after his death a portion of his property should be spent on charity, he should not wait for his death but spend it wherever he desires even during his lifetime; for it is possible that after his death his successors may not act upon his will or he may not get an opportunity to write a will.
Nahjul-Balagha, p. 512 Saying No. 254
The Holy Prophet (S) said: “Give alms and cure your sick persons by it, because alms can surely remove your bad fortunes and ailments; and it causes prolongation of your lifetimes and increases your rewards.”
Kanz-ul-‘Ummal, vol. 6, p. 371
It is narrated from the Holy Prophet (S) who said:
“When I ascended to the sky, I saw three lines written on the door of Heaven:
The first line: In the Name of Allah, the Beneficent, the Merciful; I am Allah and there is no god save Me that My Grace preceeds My wrath.
The second line: In the Name of Allah, the Beneficent the Merciful; charity is repaid ten times and loan eighteen times, and regard for kinship thirty times.
The third line: He who understands My Rank and My Lordship should never accuse Me regarding sustenance.”
Al – Ithna ‘Ashariyyah, p. 85
Tawus-ibn-il-Yaman said that he heard when Imam ‘Ali-ibn-il-Husain, Zainul-‘Abidin (‘a) that said the epithets of a believer were five then he asked him (‘a) about them and he answered: “Piety in private, donating charity at the time of need, patience when misfortunes come, tolerance at the time of anger, truthfulness when there is fear.”
Al-Khisal by Saduq, p. 127