Sunan an Nasai
4476
Sahih+2

It was narrated from Ibn Al-Had, from 'Abdullah bin Dinar, from 'Abdullah bin 'Umar, that he heard the Messenger of Allah (ﷺ) say:"When two people meet to engage in trade, the transaction between them is not binding until they separate, unless they have chosen to conclude the transaction

SahihAbu Ghuddah
SahihAl-Albani