It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him), he says: I asked, "O Messenger of Allah! Which oppression is the greatest?" You (peace and blessings be upon him) said: "A piece of land, which a man snatches from his brother's right. Whoever seizes even as much land as a pebble in this way, on the Day of Resurrection, he will be made to wear a collar reaching to the depths of the earth, and no one knows the depth of the earth except the One who created it."