Sahih Muslim | Book 22 | Hadith Number 4878

Narrated by Abu Tufail
Abu Tufail reported: 'Ali was asked whether Allah's Messenger (may peace be upon him) had showed special favour (by disclosing to him) a thing (which he kept secret from others). Thereupon he said: Allah's Messenger (may peace be upon him) singled us not

for (disclosing to us) anything (secret) which he did not make public, (but those few things) which lie in the sheath of my sword. He drew out the written document contained in it and on that (it was mentioned): Allah cursed him who sacrificed for anyone else besides Allah ; and Allah cursed him who stole the signposts (demarcating the boundary lines of the) land; and Allah cursed him who cursed his father; and Allah cursed him who accommodated an innovator (in religion).