Musnad Ahmad 30:218

Sufyan narrated to us, from Abu al-Zinad, from al-A'raj, from Abu Hurayrah—it was said to Sufyan: "From the Prophet, may Allah bless him and grant him peace?" He said: "Yes"—: "Delaying payment by the wealthy is injustice. And if one of you is referred to a solvent person, let him accept the referral."