Bhagwat Geeta 18.5: Actions based upon sacrifice, charity, and penance should never be abandoned; they must certainly be performed. Indeed, acts of sacrifice, charity, and penance are purifying even for those who are wise.
It is an act of duty to give according to one’s capacity. The Bhaviṣhya Purāṇ states: dānamekaṁ kalau yuge [v5] “In the age of Kali, giving in charity is the means for purification.” The Ramayan states this too:
pragaṭa chāri pada dharma ke kali mahuñ ek pradhāna
jena kena bidhi dīnheṅ dāna karai kalyāna [v6]
“Dharma has four basic tenets, one amongst which is the most important in the age of Kali—give in charity by whatever means possible.” The act of charity bestows many benefits. It reduces the attachment of the giver toward material objects; it develops the attitude of service; it expands the heart, and fosters the sentiment of compassion for others. Hence, most religious traditions follow the injunction of giving away one-tenth of one’s earnings in charity. The Skandh Purāṇ states:
nyāyopārjita vittasya daśhamānśhena dhīmataḥ
kartavyo viniyogaśhcha īśhvaraprityarthameva cha [v7]
“From the wealth you have earned by rightful means, take out one-tenth, and as a matter of duty, give it away in charity. Dedicate your charity for the pleasure of God.” Charity is classified as proper or improper, superior or inferior, according to the factors mentioned by Shree Krishna in this verse. When it is offered freely from the heart to worthy recipients, at the proper time, and at the appropriate place, it is bequeathed to be in the mode of goodness.