Sayyidah Khawlah (may Allah be pleased with her) said: The Messenger of Allah (peace and blessings be upon him) said: "Allah does not purify a community in which the weak cannot take their right from the strong without hindrance." Then he said: "Whoever's creditor departs from him with his right while pleased with him, the creatures of the earth and the fish of the water pray for mercy for him; and whoever's creditor departs displeased, injustice is recorded against him for every day, night, week and month."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 20961