From Sahih Bukhari (Hadith 4989):
Narrated Zaid bin Thabit:Abu Bakr sent for me and said, "You used to write the Divine Revelations for Allah's Messenger (ﷺ) : So you should search for (the Qur'an and collect) it." I started searching for the Qur'an till I found the last two Verses of Surat at-Tauba with Abi Khuza`ima Al-Ansari and I could not find these Verses with anybody other than him. (They were): 'Verily there has come unto you an Apostle (Muhammad) from amongst yourselves. It grieves him that you should receive any injury or difficulty
Reference: Bukhari 4989