Allah the Exalted said:
٢٧٦ - باب النهي عن الغش والخداع
Allah the Exalted said:
And those who harm believing men and believing women for [something] other than what they have earned [i.e., deserved] have certainly borne upon themselves a slander and manifest sin.
Abū Hurayra (may Allah be pleased with him) reported that the Messenger of Allah ﷺ said: "Whoever bears arms against us is not one of us, and whoever cheats us is not one of us." Narrated by Muslim. In another narration of his: the Messenger of Allah ﷺ passed by a heap of food and put his hand into it, and his fingers met with moisture. He said: "What is this, O owner of the food?" He said: The rain struck it, O Messenger of Allah. He said: "Why did you not put it on top of the food so that people could see it! Whoever cheats us is not one of us."
And from him: the Messenger of Allah ﷺ said: "Do not make sham bids (najsh)." Agreed upon.
Ibn ʿUmar (may Allah be pleased with them) reported that the Prophet ﷺ forbade najsh (making a sham bid to drive up a price). Agreed upon.
And from him, he said: A man mentioned to the Messenger of Allah ﷺ that he was being deceived in sales. So the Messenger of Allah ﷺ said: "When you trade with anyone, say: No deception." Agreed upon. Al-khilāba is with a dotted khāʾ vowelled with a kasra and a single-dotted bāʾ; it means deception.
Abū Hurayra (may Allah be pleased with him) said: The Messenger of Allah ﷺ said: "Whoever incites a man's wife or his slave against him is not one of us." Narrated by Abū Dāwūd. Khabbaba is with a dotted khāʾ, then a doubled single-dotted bāʾ: that is, he corrupted and deceived him.