A juz (plural ajza), also called a para in South Asia, is one of thirty roughly equal divisions of the written Quran. The division is made by length rather than by meaning, so a juz usually begins and ends in the middle of a surah; each is further split into two hizb and each hizb into quarters. Reciting one juz a night completes the whole Quran across a lunar month, a rhythm tied above all to Ramadan, when the entire text is recited in the nightly tarawih prayers. This portion spans Ya-Sin 36:28 through Az-Zumar 39:31. Ya-Sin, often called the heart of the Quran and recited for the dying, resolves in vivid scenes of resurrection. As-Saffat ('Those Ranged in Ranks') recounts the near-sacrifice of Abraham's son, and Sad treats David, Solomon and Job before Az-Zumar ('The Throngs') opens.
Al-Ahzab's material on the Battle of the Trench (33:9-27), fought in 5 AH when Medina was besieged by a coalition of Meccan and allied tribes, is read by classical historians alongside the near-contemporary biographical literature (sira) on the Prophet's life as one of the clearest points of overlap between Quranic text and independently transmitted historical narrative, the trench itself, dug on the advice of the Persian companion Salman al-Farisi, being remembered in both traditions. Ya-Sin, which this juz reaches by its end, is widely recited in the modern period at the bedside of the dying and after death, a custom resting on hadith describing its recitation as easing a soul's departure, though the practice's history within the Quranic text's original context is devotional rather than legislated.