قَوْلُهُ تَعَالَى: {فَارْتَدَّا عَلَى آثَارِهِمَا قَصَصًا} [الكهف: 64]
That he differed with Hur bin Qais bin Hisn Al-Fazari regarding the companion of (the Prophet) Moses. Ibn ʿAbbas said that he was Al Khadir. Meanwhile, Ubai bin Kaʿb passed by them and Ibn ʿAbbas called him, saying "My friend (Hur) and I have differed regarding Moses' companion, whom Moses asked the way to meet. Have you heard the Prophet ﷺ mentioning something about him? He said, "Yes. I heard Messenger of Allah ﷺ 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? (18.64) So they went back retracing their footsteps, and found Khadir. (And) what happened further to them is narrated in the Holy Qur'an by Allah. (18.54 up to 18.82) (Using translation from Bukhārī 74)
إِنِّي تَمَارَيْتُ وَصَاحِبِي هَذَا فِي صَاحِبِ مُوسَى الَّذِي سَأَلَ السَّبِيلَ إِلَى لِقَائِهِ هَلْ سَمِعْتَ رَسُولَ اللهِ ﷺ يَذْكُرُ شَيْئًا؟ قَالَ أَيْ نَعَمْ سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ بَيْنَا مُوسَى فِي مَلَأٍ مِنْ بَنِي إِسْرَائِيلَ إِذْ جَاءَهُ رَجُلٌ فَقَالَ هَلْ تَعْلَمُ أَحَدًا أَعْلَمَ مِنْكَ؟ فَقَالَ مُوسَى عَلَيْهِ السَّلَامُ لَا فَأَوْحَى اللهُ إِلَى مُوسَى بَلَى عَبْدُنَا خَضِرٌ فَسَأَلَ مُوسَى عَلَيْهِ السَّلَامُ السَّبِيلَ إِلَى لُقِيِّهِ فَجَعَلَ اللهُ لَهُ الْحُوتَ آيَةً وَقِيلَ إِذَا فَقَدْتَ الْحُوتَ فَارْجِعْ فَإِنَّكَ سَتَلْقَاهُ فَكَانَ مُوسَى عَلَيْهِ السَّلَامُ يَتْبَعُ أَثَرَ الْحُوتِ فِي الْبَحْرِ قَالَ فَتَى مُوسَى لِمُوسَى {أَرَأَيْتَ إِذْ أَوَيْنَا إِلَى الصَّخْرَةِ فَإِنِّي نَسِيتُ الْحُوتَ وَمَا أَنْسَانِيهُ إِلَّا الشَّيْطَانُ أَنْ أَذْكُرَهُ} [الكهف 63] قَالَ مُوسَى عَلَيْهِ السَّلَامُ {ذَلِكَ مَا كُنَّا نَبْغِ فَارْتَدَّا عَلَى آثَارِهِمَا قَصَصًا فَوَجَدَا} [الكهف 65] خَضِرًا فَكَانَ مِنْ شَأْنِهِمَا مَا قَصَّ اللهُ فِي كِتَابِهِ