Hadith
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

Imam Amir-ul-Mu'mineen ‘Ali (‘a)

Giving charity in secret will compensate for wrong-doings and sins, and giving charity in public will increase your wealth.

نهج البلاغة : 163، طبعة صبحي الصالح

Imam Amir-ul-Mu'mineen ‘Ali (‘a)

God will shade seven (groups of people) under His Shadow on the Day when there is no shadow other than His.

One are those who give charity in the most secret way so that their right hand does not know what their left has given in charity!


Imam Sadiq quoted

The plains of the Day of Judgment will be full of Fire except for the shadow of the believer, for his acts of charity will shade him.


Hanan ibn Sodayr quoted on the authority of his father on the authority of Imam Baqir

Giving charity will fend off seventy of this world's calamities and save you from a bad death in addition to granting you the rewards for the Hereafter.