Sahih al-Bukhari Book 34, Hadith 70
A person came to the Prophet (ﷺ) and told him that he was always betrayed in purchasing. The Prophet (ﷺ)
told him to say at the time of buying, "No cheating."
I bartered my property in Khaibar to 'Uthman (chief of the faithful believers) for his property in Al-Wadi. When we finished the deal, I left immediately and got out of his house lest he should cancel the deal, for the tradition was that they buyer and the seller had the option of canceling the bargain unless they separated. When out deal was completed, I came to know that I have been unfair to 'Uthman, for by selling him my land I caused him to be in a land of Thamud, at a distance of three days journey from Al-Madina, while he made me neared to Al-Madina, at a distance of three days journey from my former land.
Allah's Messenger (ﷺ) said, "An army will invade the Ka`ba and when the invaders reach Al-Baida', all the ground will sink and swallow the whole army." I said, "O Allah's Messenger (ﷺ)! How will they sink into the ground while amongst them will be their markets (the people who worked in business and not invaders) and the people not belonging to them?" The Prophet (ﷺ) replied, "all of those people will sink but they will be resurrected and judged according to their intentions."