All perfect praise be to Allaah, the Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
You are neither obliged to shelter your friend nor to feed him, and you are not obliged to bear an expense that is hard for you to bear.
In general, sheltering your friend and feeding him are among the moral behaviours and good customs, and if you have a sincere intention [of doing this for the Sake of Allaah], then you will get a great reward from Allaah. Surely, Allaah will not allow a good deed to be lost.
However, you should balance this expense in a manner by which you do not refrain from a charity that you can give and at the same time you do not bear more than what you can actually bear, as the condition for giving charity is that the charity should be a surplus over the need of the one who is giving it.
The Fiqh Encyclopaedia reads: “The richness that is considered in regard to giving a voluntary charity is that the person should have a surplus over his need and the need of those whom he is obliged to spend on, so he may give in charity from it.”
Allaah Knows best.