It is narrated from Sayyiduna Abu Hurairah, may Allah be pleased with him, that the Messenger of Allah, peace and blessings be upon him, said: "Delaying repayment of a debt by a wealthy person is injustice, and when any of you is directed towards a wealthy person (to collect the debt from him), he should go to him."
Hadith Referenceالسنن المأثورة / باب في البيوع / 238
Hadith Takhrijصحیح بخاری، الحوالات، باب في الحوالة وهل يرجع في الحوالة، رقم : 2287 ، صحیح مسلم ، المساقاة، باب تحريم مطل الغنى، رقم : 1564