Quran 18:70 from Surah Al-Kahf on Divine Marvels.
قَالَ فَإِنِ ٱتَّبَعۡتَنِي فَلَا تَسۡـَٔلۡنِي عَن شَيۡءٍ حَتَّىٰٓ أُحۡدِثَ لَكَ مِنۡهُ ذِكۡرٗا
English translation: He said Then if you follow me (do) not ask me about anything until I present to you of it a mention
Transliteration: qala fa-ini ittaba'tani fala tasalni an shayin hatta uh'ditha laka min'hu dhik'ran