I heard Abu Juhaifa saying, "I asked ʿAli 'Have you got any Divine literature apart from the Qur'an?' (Once he said...apart from what the people have?) ʿAli replied, '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 we have what is written in this paper.' I asked, 'What is written in this paper?' He replied, 'Al-ʿAql (the regulation of Diya), about the ransom of captives, and the Judgment that a Muslim should not be killed in Qisas (equality in punishment) for killing a disbeliever." (See Hadith No. 283,Vol. 4)  

سَأَلْتُ عَلِيًّا ؓ هَلْ عِنْدَكُمْ شَىْءٌ مَا لَيْسَ فِي الْقُرْآنِ وَقَالَ مَرَّةً مَا لَيْسَ عِنْدَ النَّاسِ فَقَالَ وَالَّذِي فَلَقَ الْحَبَّ 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