Sunan an-Nasa'i 4688
سنن النسائي#4688Sahihأَخْبَرَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " إِذَا أُتْبِعَ أَحَدُكُمْ عَلَى مَلِيءٍ فَلْيَتْبَعْ وَالظُّلْمُ مَطْلُ الْغَنِيِّ " .
It was narrated that Abu Hurairah said:"The Messenger of Allah said: 'If one of you is referred to a rich man (to help repay a debt), he should accept that referral, and (wrongdoing) is when a rich man takes a long time to repay a debt
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 44:240