Language:
كتاب الحج
25  
Hajj (Pilgrimage)
(30)
Chapter: Reciting Talbiya on entering a valley
(30)
باب التَّلْبِيَةِ إِذَا انْحَدَرَ فِي الْوَادِي
Sahih al-Bukhari 1555

Narrated Mujahid:

I was in the company of Ibn `Abbas and the people talked about Ad-Dajjal and said, "Ad-Dajjal will come with the word Kafir (non-believer) written in between his eyes." On that Ibn `Abbas said, "I have not heard this from the Prophet (ﷺ) but I heard him saying, 'As if I saw Moses just now entering the valley reciting Talbyia. ' "

حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، قَالَ حَدَّثَنِي ابْنُ أَبِي عَدِيٍّ، عَنِ ابْنِ عَوْنٍ، عَنْ مُجَاهِدٍ، قَالَ كُنَّا عِنْدَ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ فَذَكَرُوا الدَّجَّالَ أَنَّهُ قَالَ ‏"‏ مَكْتُوبٌ بَيْنَ عَيْنَيْهِ كَافِرٌ ‏"‏‏.‏ فَقَالَ ابْنُ عَبَّاسٍ لَمْ أَسْمَعْهُ وَلَكِنَّهُ قَالَ ‏"‏ أَمَّا مُوسَى كَأَنِّي أَنْظُرُ إِلَيْهِ إِذِ انْحَدَرَ فِي الْوَادِي يُلَبِّي ‏"‏‏.‏
Reference : Sahih al-Bukhari 1555
In-book reference : Book 25, Hadith 41
USC-MSA web (English) reference : Vol. 2, Book 26, Hadith 626
  (deprecated numbering scheme)