كتاب الإيمان
1
The Book of Faith
(76)
Chapter: About (The Lote-Tree of the Utmost Boundary)
(76)
باب فِي ذِكْرِ سِدْرَةِ الْمُنْتَهَى ‏‏
Sahih Muslim 174 c

Zirr b. Hubaish narrated it on the authority of 'Abdullah (that the words of Allah):

" 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.
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 ‏.‏
Reference : Sahih Muslim 174 c
In-book reference : Book 1, Hadith 341
USC-MSA web (English) reference : Book 1, Hadith 332
  (deprecated numbering scheme)