Sahih Al Bukhari (78)

حَدَّثَنَا أَبُو القَاسِمِ خَالِدُ بْنُ خَلِيٍّ قَاضِي حِمْصَ قَالَ: حَدَّثَنَا مُحَمَّدُ بْنُ حَرْبٍ، قَالَ: حَدَّثَنَا الأَوْزَاعِيُّ، أَخْبَرَنَا الزُّهْرِيُّ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ بْنِ عُتْبَةَ بْنِ مَسْعُودٍ، عَنِ ابْنِ عَبَّاسٍ، أَنَّهُ تَمَارَى هُوَ وَالحُرُّ بْنُ قَيْسِ بْنِ حِصْنٍ الفَزَارِيُّ فِي صَاحِبِ مُوسَى، فَمَرَّ بِهِمَا أُبَيُّ بْنُ كَعْبٍ، فَدَعَاهُ ابْنُ عَبَّاسٍ فَقَالَ: إِنِّي تَمَارَيْتُ أَنَا وَصَاحِبِي هَذَا فِي صَاحِبِ مُوسَى الَّذِي سَأَلَ السَّبِيلَ إِلَى لُقِيِّهِ، هَلْ سَمِعْتَ رَسُولَ اللَّهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ يَذْكُرُ شَأْنَهُ؟ فَقَالَ أُبَيٌّ: نَعَمْ، سَمِعْتُ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ يَذْكُرُ شَأْنَهُ يَقُولُ: "بَيْنَمَا مُوسَى فِي مَلَإٍ مِنْ بَنِي إِسْرَائِيلَ، إِذْ جَاءَهُ رَجُلٌ فَقَالَ: أَتَعْلَمُ أَحَدًا أَعْلَمَ مِنْكَ؟ قَالَ مُوسَى: لاَ، فَأَوْحَى اللَّهُ عَزَّ وَجَلَّ إِلَى مُوسَى: بَلَى، عَبْدُنَا خَضِرٌ، فَسَأَلَ السَّبِيلَ إِلَى لُقِيِّهِ، فَجَعَلَ اللَّهُ لَهُ الحُوتَ آيَةً، وَقِيلَ لَهُ: إِذَا فَقَدْتَ الحُوتَ فَارْجِعْ، فَإِنَّكَ سَتَلْقَاهُ، فَكَانَ مُوسَى صَلَّى اللَّهُ عَلَيْهِ يَتَّبِعُ أَثَرَ الحُوتِ فِي البَحْرِ، فَقَالَ فَتَى مُوسَى لِمُوسَى: (أَرَأَيْتَ إِذْ أَوَيْنَا إِلَى الصَّخْرَةِ فَإِنِّي نَسِيتُ الحُوتَ وَمَا أَنْسَانِيهِ إِلَّا الشَّيْطَانُ أَنْ أَذْكُرَهُ)، قَالَ مُوسَى: (ذَلِكَ مَا كُنَّا نَبْغِي فَارْتَدَّا عَلَى آثَارِهِمَا قَصَصًا)، فَوَجَدَا خَضِرًا، فَكَانَ مِنْ شَأْنِهِمَا مَا قَصَّ اللَّهُ فِي كِتَابِهِ "

Ibn `Abbas (may Allah be pleased with him) narrated that he differed with Al Hur ibn Qays ibn Hisn Al Fazary regarding the companion of (Prophet) Moses. Ibn `Abbas said that he was Khadir. Meanwhile, Ubay ibn Ka`b passed by them and Ibn `Abbas called him, saying: "My friend (Al Hur) and I have differed regarding Moses' companion whom Moses asked the way to meet. Have you heard the Prophet (peace be upon him) mentioning something about him? He said: "Yes, I heard Allah's Messenger (peace be upon him) saying: "While Moses was sitting in the company of some Israelites, a man came and asked him: "Do you know anyone who is more learned than you? Moses replied: "No." So, Allah sent the Divine Inspiration to Moses: 'Yes, Our slave Khadir (is more learned than you.)' Moses asked (Allah) how to meet him (Khadir). So, Allah made the fish as a sign for him and he was told that when the fish was lost, he should return (to the place where he had lost it) and there he would meet him (Al Khadir). So, Moses went on looking for the sign of the fish in the sea. The servant-boy of Moses said to him: Do you remember when we betook ourselves to the rock, I indeed forgot the fish, none but Satan made me forget to remember it. On that Moses said: 'That is what we have been seeking? So, they went back retracing their foot-steps, and found Khadir. (And) what happened further to them is narrated in the Glorious Qur'an by Allah. (154 up to 182)