فَأَمَّا مَن ثَقُلَتْ مَوَازِينُهُ
As for him, whose deeds weigh heavy in the scales,
فَهُوَ فِي عِيشَةٍ رَّاضِيَةٍ
he will have a pleasing life.
وَأَمَّا مَنْ خَفَّتْ مَوَازِينُهُ
But as for him, whose deeds weigh light in the scales,
فَأُمُّهُ هَاوِيَةٌ
his home will be the Abyss.
English translation: Ali Quli Qarai
The Two Scales: a pleasing life, or the Abyss as mother (101:6-9)
With the cosmos undone, the surah sorts humanity by the Balance: {as for him whose scales weigh heavy — a well-pleasing life; and as for him whose scales weigh light — his mother shall be Hāwiya}. The present sources converge on what is weighed and diverge instructively on the mīzān itself. al-Ṭabarsī notes that both clauses speak only of good deeds ("weigh heavy / weigh light"), never of weighing sins, "because weight is an expression of worth and consequence, and the evil deed has no worth" — so the verse measures the magnitude of a person's good before God. al-Ṭāṭabāʾī (al-Mīzān) makes the same division ontological: the heavy is "faith and the kinds of obedience," which "have rank with God," the light is "disbelief and the kinds of disobedience," and the two "differ in effect — the heavy entails felicity, the light wretchedness." al-Ṭūsī preserves the fullest scholastic debate: al-Farrāʾ equates mawāzīn with awzān; al-Ḥasan, al-Jubbāʾī and "most exegetes" posit a literal Balance with two pans; and three competing accounts follow of what is actually weighed — a light-versus-darkness marking obedience and disobedience, the scrolls of deeds, or (a third view) the mīzān as a metaphor for justice (ʿadl), "because deeds are accidents that cannot literally be weighed." al-Mīzān independently reaches that metaphorical reading, calling ʿīsha rāḍiya itself a "rational metaphor" — the life is called "well-pleasing" though it is its owner who is pleased.
On {his mother shall be Hāwiya} the sources offer two classic explanations, and all of them record both. The dominant reading (al-Ṭabarsī, al-Ṭūsī, al-Mīzān): Hāwiya is Hell, called "mother" because the damned "takes refuge in it as a child takes refuge in its mother" — al-Mīzān grounding the name in huwiyy, the "falling" of the one cast down "to the lowest of the low" (al-Tīn 95:5-6). The second, from Abū Ṣāliḥ (and al-Qummī, echoed by al-Burhān): umm is umm al-raʾs, "the crown of the head," because the sinner is flung into the Fire head-first. al-Ṭabāṭabāʾī fairly reports this view but judges it "remote," since the later pronoun in {what is it?} would then lack a clear referent; al-Ṭabarsī adds Qatāda's note that "his mother is fallen" was already an Arabic idiom for catastrophe.
al-Baḥrānī's al-Burhān supplies the narrative layer. Two mīzān traditions through al-Kulaynī make devotional what the others make doctrinal: "nothing in the Balance is heavier than the blessing upon Muḥammad and the Family of Muḥammad," and "tasbīḥ is half the Balance, al-ḥamdu li-llāh fills it, Allāhu akbar fills what is between heaven and earth." al-Burhān then carries two sharply sectarian-polemical reports — from al-Riḍā and from Ibn Shahrāshūb — applying {whose scales weigh heavy} to ʿAlī b. Abī Ṭālib and {whose scales weigh light} to those who "denied the walāya of ʿAlī." These are recorded here strictly as transmitted, not endorsed, and are flagged for human review. The Enlightening Commentary harmonizes the spectrum: the plural mawāzīn points (via tradition) to the Imams as the "scales by which deeds are measured," while Imam al-Ṣādiq's answer "the scales and Justice are the same" preserves al-Ṭūsī's metaphor of ʿadl; its closing section restates that the benediction on Muḥammad and his progeny is the deed that tips a light scale heavy.