Sahih Bukhari Volume 009, Book 093, Hadith Number 553.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 93. Oneness, Uniqueness of Allah (Tawheed)
Narrated By Ibn 'Abbas : The Prophet stood before Musailama (the liar) who was sitting with his companions then, and said to him, "If you ask me for this piece (of palm-leaf stalk), even then I would not give it to you. You cannot avoid what Allah has ordained for you, and if you turn away from Islam, Allah will surely ruin you!"