The brothers shall appropriate nothing to themselves, neither a house nor place nor anything. And as pilgrims and strangers 1 in this world, serving the Lord in poverty and humility, let them go confidently in quest of alms, nor ought they to be ashamed, because the Lord made Himself poor for us in this world. This, my dearest brothers, is the height of the most sublime poverty which has made you heirs and kings of the kingdom of heaven: poor in goods, but exalted in virtue. Let that be your portion, for it leads to the land of the living; 2 cleaving to it unreservedly, my best beloved brothers, for the Name of our Lord Jesus Christ, never desire to possess anything else under heaven.
And wheresoever the brothers are and may find themselves, let them mutually show among themselves that they are of one household. And let one make known his needs with confidence to the other, for, if a mother nourishes and loves her carnal son, how much more earnestly ought one to love and nourish his spiritual brother! And if any of them should fall into illness, the other brothers must serve him as they would wish to be served themselves.
–From the Second Rule of St. Francis (read it all here)