Text 20

datavyam iti yad danam
diyate ’nupakarine
dese kale ca patre ca
tad danam sattvikam smrtam

Translation

Charity given out of duty, without expectation of return, at the proper time and place, and to a worthy person is considered to be in the mode of goodness. 

Commentary by Srila Prabhupada 

In the Vedic literature, charity given to a person engaged in spiritual activities is recommended. There is no recommendation for giving charity indiscriminately. Spiritual perfection is always a consideration. Therefore charity is recommended to be given at a place of pilgrimage and at lunar or solar eclipses or at the end of the month or to a qualified brahmana or a Vaishnava (devotee) or in temples. Such charities should be given without any consideration of return. Charity to the poor is sometimes given out of compassion, but if a poor man is not worth giving charity to, then there is no spiritual advancement. In other words, indiscriminate charity is not recommended in the Vedic literature.

Commentary by Sri Visvanatha Cakravarti Thakur

One should be convinced that the gift should be given (datavam iti). It is understood here that there is no desire for personal gain.