Short answers, pulled from the story.
Dāna is a Sanskrit and Pali word meaning the virtue of generosity, charity, or giving of alms. In Hinduism, Buddhism, Jainism, and Sikhism, it refers to the practice of giving without expectation of return, directed toward individuals in need, monastic communities, or public benefit projects.
The Rigveda contains the earliest discussion of dāna in the Vedas. Book 10, Hymn 117, translated by Ralph T. H. Griffith, describes the moral obligation to give to those in distress and warns that one who eats without sharing bears all guilt.
The Bhagavad Gita, in verses 17.20 through 17.22, divides charity into three types based on the gunas: sattvikam (pure giving without expectation, at the right time and place, to a worthy person), rajas (ego-driven or reluctant giving expecting a return), and tamas (contemptuous giving to unworthy recipients at the wrong time or place).
Dhamma-dāna is the gift of the Buddha's teachings and is considered by the Buddha to surpass all other forms of giving. It includes monks who preach or recite from the Tripitaka, teachers of meditation, and those who encourage others to keep precepts.
Jainism identifies four specific types of dāna: Ahara-dana (donation of food), Ausadha-dana (donation of medicine), Jnana-dana (donation of knowledge), and Abhaya-dana (giving protection or asylum to someone facing threat). Dāna is one of ten means to gain positive karma in Jain thought.
Al-Biruni, who lived in India for approximately sixteen years, wrote that it was obligatory for Hindus to give alms every day as much as possible. He recorded that some allocated one-ninth of their after-tax income to charity, while others divided their income into four portions with one portion reserved for alms.