«فَلَا تَسْأَلْنِي عَنْ شَيْءٍ حَتَّىٰ أُحْدِثَ لَكَ مِنْهُ ذِكْرًا»
“Do not ask me about anything until I myself mention it to you.” (al-Kahf 18:70)
“Shayʾ” is a broad noun, yet this instruction concerns the events that will unfold on Moses’ journey with his companion. It does not prohibit every question about every subject for all time.
The scope of a general word can be determined by the speaker, setting and explicit temporal limit. Good interpretation preserves both the broad surface form and the restricted practical application made clear by the dialogue.