Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) says that Allah Almighty has made it obligatory upon the wealthy to help the poor with such an amount of their wealth as suffices them. If they are hungry or naked, and the wealthy did not do this, then Allah Almighty has the right to hold them to account on the Day of Resurrection and to punish them for it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الصدقات / 13206