Right understanding of Dāna
In Buddhism the merit created is greater if you give food to a monk when compared with giving to a prisoner for example, it doesn't mean you should not help the prisoner, it means that you create more merits by helping pure and enlighted beings to survive, there are many stories on the dhammapada about it.

Think as if you are helping the Sangha to survive, so they can benefit inumerous beings, the impact in the world is bigger and so the merit earned.