Sayyiduna Abu Hurayrah (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) said: "There are three people to whom Allah will not speak, nor will He purify them, and for them is a painful punishment: (1) a person who sells his goods after Asr, swearing an oath that he bought it for so much, and the buyer, believing him, takes the goods from him, although the matter was not so; (2) a person who pledges allegiance to an imam only for the sake of the world: if he gets it, he fulfils it, that is, he stays loyal, and if he does not get any of the world, he does not stay loyal; (3) a servant who withholds surplus water in the wilderness from travellers."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10796
Ibn Abi Awfa (may Allah be pleased with him) says that a man had his goods set out, and he swore by Allah that he had been offered so much for them, that he had bought them for so much, although that amount had not been given for them. Then this verse was revealed: "Indeed, those who exchange the covenant of Allah and their oaths for a small price" [Surah Al Imran: 77]. Ibn Abi Awfa (may Allah be pleased with him) said: The one who bids up the price is a consumer of usury (riba) and a betrayer.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10797