Mishkat al-Masabih 8 The Excellent Qualities of the Qur’an كتاب فضائل القرآن 31

وَعَنْ عُقْبَةَ بْنِ عَامِرٍ قَالَ: سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: «لَوْ جُعِلَ الْقُرْآنُ فِي إِهَابٍ ثُمَّ أُلْقِيَ فِي النَّار مَا احْتَرَقَ» . رَوَاهُ الدَّارمِيّ

‘Uqba b. ‘Amir said he heard God’s messenger say, “If the Qur’ān were put in a skin and thrown into the fire it would not burn.” Dārimī transmitted it.