It was narrated from Jabir bin 'Abdullah that the Messenger of Allah (ﷺ) said:
"May Allah have mercy on a person who is lenient when he sells, lenient when he buys, and lenient when he asks for payment. " (FR)
English reference (FR): Vol. 3, Book 12, Hadith 2203 (FR)
Arabic reference (FR): Book 12, Hadith 2287 (FR)