It is narrated from Sayyiduna Ismah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "In Islam there is no (unjustified) reserving of land, nor najsh (deceptively bidding up a price)."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 14541