Sahih al-Bukhari 3355
Narrated Mujahid:
That when the people mentioned before Ibn `Abbas that the Dajjal would have the word Kafir, (i.e. 
unbeliever) or the letters Kafir (the root of the Arabic verb 'disbelieve') written on his forehead, I 
heard Ibn `Abbas saying, "I did not hear this, but the Prophet (ﷺ) said, 'If you want to see Abraham, then 
look at your companion (i.e. the Prophet) but Moses was a curly-haired, brown man (who used to 
ride) a red camel, the reins of which was made of fires of date-palms. As if I were now looking down 
a valley."
حَدَّثَنِي بَيَانُ بْنُ عَمْرٍو، حَدَّثَنَا النَّضْرُ، أَخْبَرَنَا ابْنُ عَوْنٍ، عَنْ مُجَاهِدٍ، أَنَّهُ سَمِعَ ابْنَ عَبَّاسٍ ـ رضى الله عنهما ـ وَذَكَرُوا لَهُ الدَّجَّالَ بَيْنَ عَيْنَيْهِ مَكْتُوبٌ كَافِرٌ أَوْ ك ف ر‏.‏ قَالَ لَمْ أَسْمَعْهُ وَلَكِنَّهُ قَالَ ‏
"‏ أَمَّا إِبْرَاهِيمُ فَانْظُرُوا إِلَى صَاحِبِكُمْ، وَأَمَّا مُوسَى فَجَعْدٌ آدَمُ عَلَى جَمَلٍ أَحْمَرَ مَخْطُومٍ بِخُلْبَةٍ، كَأَنِّي أَنْظُرُ إِلَيْهِ انْحَدَرَ فِي الْوَادِي ‏"‏‏.‏