When Hazrat Ali [pbuh] was in Yemen, he sent some gold in its ore to Prophet Muhammad [pbuh].The Prophet distributed it among Al-Aqra' bin Habis Al-Hanzali who belonged to Bani Mujashi, 'Uyaina bin Badr Al-Fazari, 'Alqama bin 'Ulatha Al-'Amiri, who belonged to the Bani Kilab tribe and Zaid AI-Khail At-Ta'i who belonged to Bani Nabhan. So the Quraish and the Ansar became angry and said, "He gives to the chiefs of Najd and leaves us!" The Prophet said, "I just wanted to attract and unite their hearts (make them firm in Islam)." Then there came a man with sunken eyes, bulging forehead, thick beard, fat raised cheeks, and clean-shaven head, and said, "O Muhammad! Be afraid of Allah! " The Prophet said, "Who would obey Allah if I disobeyed Him? (Allah). He trusts me over the people of the earth, but you do not trust me?" A man from the people (present then), who, I think, was Khalid bin Al-Walid, asked for permission to kill him, but the Prophet prevented him. When the man went away, the Prophet said, "Out of the offspring of this man, there will be people who will recite the Quran but it will not go beyond their throats, and they will go out of Islam as an arrow goes out through the game, and they will kill the Muslims and leave the idolators. Should I live till they appear, I would kill them as the Killing of the nation of 'Aad."
Sahih Bukhari Volume 9, Book 93, Number 527