The Verse That Named Measured Recitation

Al-Muzzammil instructs the Prophet to recite the Quran 'with tartil,' generally rendered as slow, clear, measured recitation (73:4), the same term that gave its name to tartil, the entire later Islamic discipline of unhurried, correctly articulated Quranic recitation as distinct from rapid or careless reading. Classical commentators read the instruction as addressing both the practical need to receive and retain revelation accurately during the earliest period of transmission and a lasting model for how the text should always be voiced afterward, so that a single early command shaped a discipline still taught formally to reciters many centuries later.

Later scholarship on tajwid, the rules of correct pronunciation and articulation developed from this and related instructions, treats tartil as the foundational value the more detailed technical rules exist to serve, correct articulation in service of unhurried, reflective recitation rather than technical correctness pursued for its own sake. The instruction is frequently cited at the opening of tajwid textbooks as the Quranic warrant for treating recitation as a discipline requiring deliberate practice rather than simply reading aloud as one would any other text.