Mishkat al-Masabih · Book 11 · Hadith 2907
وَعَنْهُ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «مَطْلُ الْغَنِيِّ ظُلْمٌ فَإِذَا أُتْبِعَ أحدكُم على مَلِيء فَليتبعْ»
He reported God's Messenger as saying, “Delay in payment by a rich man is injustice, but when one of you is referred for payment to a wealthy* man he should accept the reference." (Bukhari and Muslim.) *Mali'. This word…