Sahih Bukhari Volume 5, Book 64, Hadith 4404

حَدَّثَنَا يَحْيَى بْنُ سُلَيْمَانَ، قَالَ أَخْبَرَنِي ابْنُ وَهْبٍ، قَالَ حَدَّثَنِي عُمَرُ بْنُ مُحَمَّدٍ، أَنَّ أَبَاهُ، حَدَّثَهُ عَنِ ابْنِ عُمَرَ ـ رضى الله عنهما ـ قَالَ كُنَّا نَتَحَدَّثُ بِحَجَّةِ الْوَدَاعِ وَالنَّبِيُّ صلى الله عليه وسلم بَيْنَ أَظْهُرِنَا، وَلاَ نَدْرِي مَا حَجَّةُ الْوَدَاعِ، فَحَمِدَ اللَّهَ وَأَثْنَى عَلَيْهِ ثُمَّ ذَكَرَ الْمَسِيحَ الدَّجَّالَ فَأَطْنَبَ فِي ذِكْرِهِ وَقَالَ ‏"‏ مَا بَعَثَ اللَّهُ مِنْ نَبِيٍّ إِلاَّ أَنْذَرَ أُمَّتَهُ، أَنْذَرَهُ نُوحٌ وَالنَّبِيُّونَ مِنْ بَعْدِهِ، وَإِنَّهُ يَخْرُجُ فِيكُمْ، فَمَا خَفِيَ عَلَيْكُمْ مِنْ شَأْنِهِ فَلَيْسَ يَخْفَى عَلَيْكُمْ أَنَّ رَبَّكُمْ لَيْسَ عَلَى مَا يَخْفَى عَلَيْكُمْ ثَلاَثًا، إِنَّ رَبَّكُمْ لَيْسَ بِأَعْوَرَ، وَإِنَّهُ أَعْوَرُ عَيْنِ الْيُمْنَى، كَأَنَّ عَيْنَهُ عِنَبَةٌ طَافِيَةٌ ‏"‏‏.

Narrated By Ibn Umar : We were talking about Hajjat-ul-Wada, while the Prophet was amongst us. We did not know what Hajjat-ul-Wada' signified. The Prophet praised Allah and then mentioned Al-Masih Ad-Dajjal and described him extensively, saying, "Allah did not send any prophet but that prophet warned his nation of Al-Masih Ad-Dajjal. Noah and the prophets following him warned (their people) of him. He will appear amongst you (O Muhammad's followers), and if it happens that some of his qualities may be hidden from you, but your Lord's State is clear to you and not hidden from you. The Prophet said it thrice. Verily, your Lord is not blind in one eye, while he (i.e. Ad-Dajjal) is blind in the right eye which looks like a grape bulging out (of its cluster).