Surat Al-Qalam - سورة القلم

ن ۚ وَالْقَلَمِ وَمَا يَسْطُرُونَ

Muhsin Khan: Nun. [These letters (Nun, etc.) are one of the miracles of the Quran, and none but Allah (Alone) knows their meanings]. By the pen and what the (angels) write (in the Records of men).