Sunan an-Nasa'i 4483
سنن النسائي#4483HasanIt was narrated from 'Amr bin Shu'aib, from his father , form his grandfather, that the Prophet said:"The two parties to a transaction have the choicer so long as they have not separated, unless they reach an agreement before parting, and it is not permissible to hasten to leave for fear that the other party may change his mind
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahHasan
Al-AlbaniHasan
Zubair Ali ZaiHasan
In-book reference: 44:35