The Surah opens with a mysterious isolated Arabic letter (Muqatta'at), Nūn, followed immediately by an oath invoking physical writing tools: "By the pen and what they inscribe, you are not... a madman."
When Muhammad first publically declared his monotheistic messages in Mecca, his own family members and tribal peers rejected him. Because his rhythmic prose closely resembled the rhyming utterances (Saj') produced by pre-Islamic fortune-tellers (Kahin), the Meccans openly labeled him a Majnūn—a person physically possessed by an erratic Jinn (demon) or suffering from severe cognitive delusions.
To a historical critic, the choice of oath objects is highly strategic.
Rather than swearing by grand cosmic bodies like the sun or moon, the text swears by the Qalam (reed pen) and the act of documentation. In the Late Antique Near East, the pen was the ultimate symbol of legal authority, bureaucratic order, and scriptural preservation used by Christian monks and Jewish rabbis.
By anchoring the Prophet's sanity to the physical, orderly technology of writing, the text attempts to counter the narrative of chaotic, erratic demonic possession with an aesthetic image of structured, heavenly scribal recording.