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 Al-Muminun 23:1 through Al-Furqan 25:20. Al-Muminun ('The Believers') describes the qualities of the successful faithful and the stages of human formation in the womb. An-Nur ('The Light') follows with laws of modesty, the Verse of Light (24:35) and the vindication of Aisha against slander, then Al-Furqan ('The Criterion') begins.
Al-Muminun's description of the stages of human formation in the womb (23:12-14), a sequence moving from a drop of fluid through clinging matter to flesh and bone, has attracted particular attention in modern apologetic and scientific-commentary literature, which reads the verses alongside embryology, though classical exegetes before the modern period generally read the same passage within the framework of ordinary Arabic anatomical vocabulary of their own era rather than as a scientific description in the later sense. An-Nur's Verse of Light (24:35), read later in the juz, comparing God's guidance to a lamp within a niche of glass, became one of the most extensively commented-upon single verses in the entire Quran, drawing sustained mystical and philosophical exposition from writers including al-Ghazali.