Tafsir of Al-Kahf 18:66

{رُشْدًا} (Guidance): It is recited with two fatḥas (rashadan) and with a ḍamma and a sukūn (rushdan). It means: knowledge possessing guidance, by which I may be guided in my religion.

If you ask: Does his need to learn from another not indicate that he was—as it is said—Moses son of Misha, not Moses son of ‘Imran? For a prophet must be the most knowledgeable of the people of his time and their leader to whom they refer in matters of religion.

I say: There is no disgrace for a prophet in acquiring knowledge from a prophet like himself. It is only disgraceful for him to acquire it from someone inferior to him.

It is narrated from Sa‘īd ibn Jubayr that he said to Ibn ‘Abbās: "Nawf, the son of Ka‘b’s wife, claims that al-Khiḍr is not the companion of Moses, and that Moses is Moses son of Misha." Ibn ‘Abbās replied: "The enemy of God has lied."

{قَالَ إِنَّكَ لَن تَسْتَطِيعَ مَعِيَ صَبْرًا * وَكَيْفَ تَصْبِرُ عَلَىٰ مَا لَمْ تُحِطْ بِهِ خُبْرًا}

(He said, "Indeed, you will never be able to have patience with me. And how can you have patience for that about which you have not encompassed any knowledge?")