Matthew 25:42-45: "For I was an hungred, and ye gave me no meat: I was thirsty, and ye gave me no drink: I was a stranger, and ye took me not in: naked, and ye clothed me not: sick, and in prison, and ye visited me not. Then shall they also answer him, saying, Lord, when saw we thee an hungred, or athirst, or a stranger, or naked, or sick, or in prison, and did not minister unto thee? Then shall he answer them, saying, Verily I say unto you, Inasmuch as ye did it not to one of the least of these, ye did it not to me."
Seems very clear here that Jesus is telling us that when we do these things for others it is as though we are doing it for Him. There are many other Scriptures that make it clearly a commandment.
there was a friend who knew a friend who was homeless 
