The Messenger of Allah ﷺ said, "Do not shun one another, do not turn your backs on one another, do not spy on one another, and do not undercut one another in trade. Be brothers, servants of Allah."
أن رسول الله ﷺ قال: لا تهجروا، ولا تدابروا، ولا تحسسوا، ولا يبع بعضكم على بيع بعض، وكونوا عباد الله إخوانا.
Muslim reported it in the Book of Righteousness and Maintaining Ties (2563:29) from Qutayba bin Saeed, Abdul-Aziz, meaning Ibn Muhammad, narrated to us, from Ala, from his father, from Abu Hurairah, and he mentioned it.