Sahih Muslim Book 10, Hadith Number 3925

Muhammad b. Ibrahim said that Abu Salama reported to him that there was between him and his people dispute over a piece of land, and he came to ‘Aisha and mentioned that to her, whereupon she said: Abu Salama, abstain from getting this land, for Allah’s Messenger (may peace be upon him) said: He who usurps even a span of land would be made to wear around his neck seven earths.