Imam Sadiq (a.s.),

One who satisfies the thirst of a person at a place where water is available; it is as if he has freed a slave. And one who does the same at a place where water is not available; it is as if he has enlivened a soul. And one who gives life to one soul; it is as if he has enlivened humanity.
Makaremul Akhlaq pg. 85, Chap. 7, part. I