It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever takes even a handspan of land in Makkah unjustly, it is as though he took it from beneath the foot of the Most Merciful; and whoever takes anything of the rest of the earth unjustly will come on the Day of Resurrection with seven earths hung as a collar around his neck."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12865