Sahih Bukhari Volume 2, Book 24, Hadith Number 489.
Narated By Al-Ahnaf bin Qais : While I was sitting with some people from Quraish, a man with very rough hair, clothes, and appearance came and stood in front of us, greeted us and said, “Inform those who hoard wealth, that a stone will be heated in the Hell-fire and will be put on the nipples of their breasts till it comes out from the bones of their shoulders and then put on the bones of their shoulders till it comes through the nipples of their breasts the stone will be moving and hitting.” After saying that, the person retreated and sat by the side of the pillar, I followed him and sat beside him, and I did not know who he was. I said to him, “I think the people disliked what you had said.” He said, “These people do not understand anything, although my friend told me.” I asked, “Who is your friend?” He said, “The Prophet said (to me), ‘O Abu Dhar! Do you see the mountain of Uhud?’ And on that I (Abu Dhar) started looking towards the sun to judge how much remained of the day as I thought that Allah’s Apostle wanted to send me to do something for him and I said, ‘Yes!’ He said, ‘I do not love to have gold equal to the mountain of Uhud unless I spend it all (in Allah’s cause) except three Dinars (pounds). These people do not understand and collect worldly wealth. No, by Allah, Neither I ask them for worldly benefits nor am I in need of their religious advice till I meet Allah, The Honorable, The Majestic.”