(17) The Book of the Prohibited actions
كتاب الأمور المنهي عنها
(284) Chapter: Prohibition of Procrastinating by a Rich Person to Fulfill his Obligation
(284) - باب تحريم مطل الغني بحق طلبه صاحبه
Riyad as-Salihin 1611 
Abu Hurairah (May Allah be pleased with him) said:
The Messenger of Allah (ﷺ) said, "It is an act of oppression on the part of a person to procrastinate in fulfilling his obligation; if the repayment of a debt due to any of you is undertaken by a rich person, you should agree to the substitution."

[Al-Bukhari and Muslim].

وعن أبي هريرة رضي الله عنه أن رسول الله صلى الله عليه وسلم قال‏:‏ ‏"‏مطل الغني ظلم وإذا أُتبع أحدكم على مليء فليتبع‏"‏ ‏(‏‏(‏متفق عليه‏.‏ معنى ‏"‏أتبع‏"‏‏:‏ أحيل‏)‏‏)‏‏.‏
Reference : Riyad as-Salihin 1611
In-book reference : Book 17, Hadith 101