Ibn 'Umar (May Allah be pleased with them) said:
A man mentioned to the Messenger of Allah (ﷺ) that he was often deceived in dealings. The Messenger of Allah (ﷺ) said to him, "When you enter into a transaction you should say: "There should be no deception."'[Al-Bukhari and Muslim]. (RU)
App reference (RU): Book 18, Hadith 72 (RU)
Arabic/English book reference (RU): Book 18, Hadith 1582 (RU)