Musnad Ahmad 26:226

Hassan narrated to us, Ibn Lahi'ah narrated to us, Ubayd Allah ibn Abi Ja'far narrated to us, from Abu Abd al-Rahman al-Hubuli, from Ibn Mas'ud, who said: I said: "O Messenger of Allah, which injustice is the most unjust?" He said: "A cubit of land that a Muslim man diminishes from the right of his brother. There is not a pebble of the earth that anyone takes, except that it will be collared around his neck on the Day of Resurrection down to the bottom of the earth, and none knows its bottom except Allah, the Almighty and Majestic, who created it."