The believers are like one body, and when one part aches the whole body feels it: the bond shows up as shared pain
A saying of the Prophet describes closeness of exactly this kind. When people have come through the same danger together, the line between my trouble and yours wears thin. One of them runs short and the others feel it before they ask, which is how one heart works.
Ukhuwwa: Brotherhood
Ukhuwwa names the bond between people who have taken each other on as family. Al-Ghazali measures it in money: leftovers at the lowest level, splitting evenly at the middle, a friend's need ahead of your own at the top. A group that reaches the middle level stops keeping separate piles, and the sharing starts to feel ordinary rather than heroic.
Īthār: Putting others before yourself
Īthār means handing over the thing you were counting on for yourself. The Quran praises people who fed and housed newcomers while going short themselves. Giving from spare change costs little, so the mark of a group like this is that nobody keeps a quiet reserve.
Amāna: Something held in trust for its owner
An amāna is placed in your hands to look after and hand back. Sufis look at money and houses this way: your name sits on them, but you are holding them for God and for whoever needs them next. Someone who lives with that in mind can give without feeling robbed, because they were never the owner in the first place.
Faqr: Poverty before God
Faqr is the settled sense that you own nothing on your own account. The Quran tells people flatly that they are the poor ones and God is the rich. Once that lands, arguments over whose coat or whose house it is lose their heat, since nobody owned any of it to begin with.