In the early days of Buddhism, the Buddha and the monks walked down the street with a begging bowl. Compassionate people would put some food in the bowl. This was what the monks ate. The practice still exists in Southern Buddhist countries.
The name may be somewhat confusing, as the monks never begged: The food was given to them completely freely by those who wished to give. No pressure ever.
The practice was spiritually beneficial to both, the monks whom it taught detachment, and to the lay people in whom it arouse compassion.