Mubīn — Clear / Clarifying

Summary: Ism fāʿil and ism mafʿūl of أَبَانَ (Form IV) that look identical on the surface due to the ajwaf root — context determines which meaning is intended. (source: session-2.md)

Root and Base Verb

Root: ب-ي-ن — note the yāʾ turns into an alif in the māḍī (weak letter / ajwaf rule).

Form	Word	Meaning
Māḍī (root verb)	بَانَ	something becomes clear (intransitive)
Muḍāriʿ	يَبِينُ	becomes clear
Form IV māḍī	أَبَانَ	to clarify something (transitive — passes to an object)
Maṣdar	بَيَان	the process/act of clarifying
Ism fāʿil / mafʿūl	مُبِين	clarifying / clarified

Note on بَيَان: the wāw/yāʾ of the root + tāʾ of Form VIII merge, producing بَيَان rather than the expected اِبتيان. (source: session-2.md)

Why Ism Fāʿil and Ism Mafʿūl Look Identical

Form IV ism fāʿil pattern: مُفْعِل; ism mafʿūl pattern: مُفْعَل. For أَبَانَ (an ajwaf/hollow verb), both surface forms converge through different phonological paths: (source: session-2.md)

Ism Fāʿil

مُبَيِّن → kasra and yāʾ are phonetically incompatible → shift → مُبِين

Ism Mafʿūl

مُبَيَّن → fatḥa moves to bāʾ → مُبَان → further smooths → مُبَون → مُبِين

Result: Both look identical — مُبِين. Context determines meaning: - Ism fāʿil: the one clarifying (active) - Ism mafʿūl: the thing that was clarified (passive)

This is a surface ambiguity arising from the phonological rules that govern ajwaf verbs — not an irregularity.

From Surah Yusuf Session 7 — لَازِم vs. مُتَعَدٍّ, and Two More Forms

Completing the root study while finishing Yūsuf 12:5 (عَدُوٌّ مُّبِينٌ):

بَانَ Is لَازِم; أَبَانَ Is مُتَعَدٍّ

بَانَ (Form I, intransitive — the action stays with the doer, like جَلَسَ) gives مُبِين the sense "clear in itself." أَبَانَ (Form IV, transitive — the action passes to an object, like أَكَلَ) gives مُبِين the sense "clarifying [something else]."

Both Senses in the Quran

إِنَّ الشَّيْطَانَ لِلْإِنسَانِ عَدُوٌّ مُّبِينٌ (Yūsuf 12:5) — lāzim sense: Satan is clear in his hostility, no ambiguity about it.
تِلْكَ آيَاتُ الكِتَابِ المُبِينِ (Yūsuf 12:1) — mutaʿaddī sense: the Book clarifies — teaching what is right and wrong.

Both readings remain valid wherever مُبِين occurs; context foregrounds one or the other.

A Second Form II — بَيَّنَ

Beyond Form I بَانَ and Form IV أَبَانَ, the root also has an active Form II, بَيَّنَ, carrying the same core sense "to clarify, make clear."

لَا يَكَادُ يُبِينُ — Pharaoh's Slander of Mūsā

"…or am I better than this one who is مَهِين, and can hardly يَكَادُ يُبِينُ [express himself]?" (al-Zukhruf 43:52)

Here the closing نُون of the full muḍāriʿ form is dropped/hidden after لَا يَكَادُ, with the object understood from context: Mūsā can barely clarify his ideas even though no explicit object is stated. مَهِين in the same āyah opened an unresolved morphological question — see [[root-hawana]].

Session References

Surah Yusuf Session 7: لَازِم/مُتَعَدٍّ distinction between بَانَ and أَبَانَ; second Form II بَيَّنَ; Pharaoh's لَا يَكَادُ يُبِينُ (al-Zukhruf 43:52) compared against Yūsuf 12:1 and 12:5.