Musa meeting with Al-Khidr and accompanying Him

Allah tells us what Musa said to that learned man, who was Al-Khidr. He was one to whom Allah had given knowledge that He had not given to Musa, just as He had given Musa knowledge that He had not given to Al-Khidr.

قَالَ لَهُ مُوسَى هَلْ أَتَّبِعُكَ

It is not permissible for an 'Alim’ of the 'Shari'ah' to patiently bear what is contrary to the Shari'ah

By saying: إِنَّكَ لَن تَسْتَطِيعَ مَعِيَ صَبْرً‌ا وَكَيْفَ تَصْبِرُ‌ عَلَىٰ مَا لَمْ تُحِطْ بِهِ خُبْرً‌ا (You can never be able to keep patient while with me. And how would you keep patient over something your comprehension cannot grasp? - 67, 68), al-Khadir (علیہ السلام) was telling Sayyidna Musa (علیہ السلام) about the fact and the reason why he would be unable to keep patient with him. He knew nothing about the reality of the thing. What he meant was that the nature of knowledge given to him was different from the knowledge of Sayyidna Musa (علیہ السلام) ، therefore, things he did would appear to be objectionable in his sight, until he himself was to apprise him of their reality. Thus, the objections he would raise against such actions would be triggered by the dictates of his mission as a prophet.