Selfless charity to poor and needy

Is selfless charity to the non-monastic poor and needy, recommended for Buddhists as part of their practice? How do the different Buddhist traditions differ from each other on this topic? Quotes from scriptures to support this, would be appreciated. The target recipients include the hardcore poor, the homeless, victims of natural disasters, abandoned old folks, orphans, shelterless disabled persons, victims of human trafficking, refugees of war, victims of oppression and other displaced persons. Animals can also be included. "Selfless" here means "concerned more with the needs of others than with one's own".