Surah Al-Kahf — Ayah 70 (18:70)
قَالَ فَإِنِ ٱتَّبَعۡتَنِي فَلَا تَسۡـَٔلۡنِي عَن شَيۡءٍ حَتَّىٰٓ أُحۡدِثَ لَكَ مِنۡهُ ذِكۡرٗا ٧٠
English translation (Saheeh International)
He said, "Then if you follow me, do not ask me about anything until I make to you about it mention [i.e., explanation]."
Brief commentary
Khidr said to Moses: If you follow me, then do not ask me about anything that you see me doing until I myself tell you the reason.