Al-Kahf - 18:70

قَالَ فَإِنِ اتَّبَعْتَنِي فَلَا تَسْأَلْنِي عَن شَيْءٍ حَتَّى أُحْدِثَ لَكَ مِنْهُ ذِكْرًا
[18:70]
He said: If you would follow me, then do not question me about any thing until I myself speak to you about it
The other said: "If then thou wouldst follow me, ask me no questions about anything until I myself speak to thee concerning it."
He said: Well, if thou go with me, ask me not concerning aught till I myself make mention of it unto thee.