Al-Qamar ('The Moon'), 55 Meccan verses, opens with the splitting of the moon as a sign of the approaching Hour (54:1). Its refrain, 'We have made the Quran easy to remember, so is there any who will take heed?', punctuates the fates of Noah's people, Ad, Thamud, Lot's town and Pharaoh. Classical commentators read the splitting of the moon (54:1) either as a sign accompanying Muhammad's call, some early sources describing it as a miracle witnessed at Mecca, or as a reference reserved for the eschatological Hour itself, a division of opinion the Quranic wording, using the past tense for a future event as the Quran often does with certain judgement, does not by itself resolve.
The refrain repeated five times through the surah, 'We have made the Quran easy to remember, so is there any who will take heed' (54:17 and elsewhere), is regularly cited in Islamic pedagogical writing on the accessibility of scripture to ordinary memorisers rather than only to scholars. The surah's repeated address to the fates of Noah's people, Ad, Thamud, Lot's town and Pharaoh, each closing with the same refrain, is read by scholars of Quranic rhetoric as a deliberate liturgical structure meant for oral recitation and memorisation as much as for continuous reading, the repetition itself functioning as a mnemonic device for early listeners who received the Quran primarily by ear. Classical commentary links the moon's splitting specifically to a sign requested by the Quraysh leadership as proof of prophethood, a request the surah presents as answered yet still met with continued denial.