Al-Mursalat ('The Emissaries'), 50 Meccan verses, swears by the sent winds or angels and repeats the refrain 'woe that Day to the deniers' through a vivid sequence of the signs of the coming Judgement. It closes the run of surahs read as evoking the terrors of the last day. Classical commentators read the 'emissaries' of the opening oath (77:1) variously as winds or as angels, a genuine interpretive division reflected across the major tafsir works rather than a settled point, since the Arabic term itself carries both senses elsewhere in the Quran. The surah's eight-fold refrain, 'woe that Day to the deniers,' recurs at almost mechanically regular intervals through its fifty verses, a structural device scholars of Quranic rhetoric identify as characteristic of the short, incantatory style of the earliest and latest Meccan material alike, closing the sequence of judgement-focused surahs that precedes the final juz.
The surah's closing description of hellfire as 'dark, gloomy shadows' rising in 'three columns' that give no relief and no shelter from the flame (77:30-33) is cited by classical commentators as one of the Quran's more visually structured single images of punishment, its threefold division read variously as smoke, sparks and heat rather than as a literal architectural description. The repeated refrain closing each section is regarded by scholars of Quranic style as one of the clearest instances of a structural device, verses functioning almost as a sung chorus, that early reciters would have used to punctuate oral performance of the text before it existed as a written, silently read document.