Altruism is the noblest concept of generosity. Not everyone can adorn himself with this trait, because it is dedicated to the few ideal persons whom are characterized by openhandedness and who attained the climax of generosity as they gave liberally while they are in urgent need. They therefore preferred charity to the settlement of their needs. The holy Quran praises the virtues of such persons:

"They give preference to them over themselves - even concerning the
things that they themselves urgently need

Imam as-Sadiq (a) said:

"The best almsgiving is that which is given by the needy."

Allah says:

They give preference to them over themselves - even concerning the things
that they themselves urgently need

The Prophet (s) was the highest example of altruism: Jabir ibn Abdullah said:
The Prophet (s) had never refused anyone's request.

Imam as-Sadiq (a) narrated: In al-Jirana, the Prophet (s) distributed the treasury among people. He gave every single individual who asked from him. As people crowded around him, they pushed him until he had to lean on a tree that scratched his back. People kept on pushing him until they took him away from that tree and his garment was hanged to one of its branches. He was shouting: "People, let me have my garment! By Allah I swear, even if I have treasures as many as the trees of Tuhama, I will distribute among you. You shall never find me coward or stingy."

The Prophet (s) used to prefer the poor to himself. He used to give them his food while he suffered hunger to the degree that he, once, tied the stone of hunger on his stomach so as to share the pains of hunger with the poor.

Imam al-Baqir (a) said:

"The Prophet (s) had never eaten his fill for three consecutive days since
Allah gave him the Divine Mission."

The The Ahl ul-Bayt (a) were copies of the Prophet in the fields of generosity and altruism.

Imam as-Sadiq (a) narrated:
Ali was the most similar to the Prophet. He used to eat bread with oil and serve people with bread and meat.

The following holy Verse was revealed for Ali and his family:

"They feed the destitute, orphans, and captives for the love of Allah, saying:
We only feed you for the sake of Allah and we do not want
any reward or thanks from you

The disciples of The The Ahl ul-Bayt have unanimously agreed that the previous holy Verse was revealed for Ali, Fatima, al-Hasan, and al-Hussein (a). Moreover, a good deal of ulema of other sects have also asserted so.