Hadith 513710
Chapter 31: Business Transactions - كتاب البيوع
حَدَّثَنَا يَحْيَى، عَنْ مَالِكٍ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " مَطْلُ الْغَنِيِّ ظُلْمٌ وَإِذَا أُتْبِعَ أَحَدُكُمْ عَلَى مَلِيءٍ فَلْيَتْبَعْ " .
Yahya related to me from Malik from Abu'z-Zinad from al Araj from Abu Hurayra that the Messenger of Allah, may Allah bless him and grant him peace, said, "Delay in payment by a rich man is injustice, but when one of you is referred for payment to a wealthy man, let him be referred."
Reference Muwatta Malik 513710
USC-MSA web (English) reference : Book 31, Hadith 85