It was narrated from Au Hurairah that the prophet granted a concession allowing estimation for 'Ararya sales, so long as they were five Wasq or less then that
Hadith ReferenceSunan an-Nasa'i / The Book of Financial Transactions / Hadith: 4545
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:متفق عليه