Sahih Muslim 174
Sahih Muslim · Book 1: The Book of Faith · About (The Lote-Tree of the Utmost Boundary)
Zirr b. Hubaish narrated it on the authority of 'Abdullah (that the words of Allah):
حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُعَاذٍ الْعَنْبَرِيُّ ، حَدَّثَنَا أَبِي ، حَدَّثَنَا شُعْبَةُ ، عَنْ سُلَيْمَانَ الشَّيْبَانِيِّ ، سَمِعَ زِرَّ بْنَ حُبَيْشٍ ، عَنْ عَبْدِ اللَّهِ ، قَالَ { لَقَدْ رَأَى مِنْ آيَاتِ رَبِّهِ الْكُبْرَى} قَالَ رَأَى جِبْرِيلَ فِي صُورَتِهِ لَهُ سِتُّمِائَةِ جَنَاحٍ .
" Certainly he saw of the greatest signs of Allah" (al-Qur'an, liii. 18) imply that he saw Gabriel in his (original) form and he had six hundred wings.