Sahih Bukhari Volume 9, Book 87, Hadith 6917

وَحَدَّثَنَا صَدَقَةُ بْنُ الْفَضْلِ، أَخْبَرَنَا ابْنُ عُيَيْنَةَ، حَدَّثَنَا مُطَرِّفٌ، سَمِعْتُ الشَّعْبِيَّ، يُحَدِّثُ قَالَ سَمِعْتُ أَبَا جُحَيْفَةَ، قَالَ سَأَلْتُ عَلِيًّا ـ رضى الله عنه ـ هَلْ عِنْدَكُمْ شَىْءٌ مِمَّا لَيْسَ فِي الْقُرْآنِ ـ وَقَالَ ابْنُ عُيَيْنَةَ مَرَّةً مَا لَيْسَ عِنْدَ النَّاسِ ـ فَقَالَ وَالَّذِي فَلَقَ الْحَبَّةَ وَبَرَأَ النَّسَمَةَ مَا عِنْدَنَا إِلاَّ مَا فِي الْقُرْآنِ إِلاَّ فَهْمًا يُعْطَى رَجُلٌ فِي كِتَابِهِ وَمَا فِي الصَّحِيفَةِ‏.‏ قُلْتُ وَمَا فِي الصَّحِيفَةِ قَالَ الْعَقْلُ، وَفِكَاكُ الأَسِيرِ، وَأَنْ لاَ يُقْتَلَ مُسْلِمٌ بِكَافِرٍ‏.‏

Narrated By Abu Juhaifa : I asked 'Ali "Do you have anything Divine literature besides what is in the Qur'an?" Or, as Uyaina once said, "Apart from what the people have?" 'Ali said, "By Him Who made the grain split (germinate) and created the soul, we have nothing except what is in the Qur'an and the ability (gift) of understanding Allah's Book which He may endow a man, with and what is written in this sheet of paper." I asked, "What is on this paper?" He replied, "The legal regulations of Diya (Blood-money) and the (ransom for) releasing of the captives, and the judgment that no Muslim should be killed in Qisas (equality in punishment) for killing a Kafir (disbeliever)."