Riyad as-Salihin

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].