Tafseer of The Calamity · Al-Qaari'a · 101:6
Then as for one whose scales are heavy [with good deeds],
Important: The Arabic source text is always authoritative. This translation is a study aid and has not been verified by scholars — do not use it as a basis for religious proof or for deriving rulings (ahkam). When in doubt, always consult the Arabic text and a qualified scholar.
And His word: فَأَمَّا مَنْ ثَقُلَتْ مَوَازِينُهُ (As for him whose scales are heavy) — He says: as for him whose scales of good deeds are heavy. By "the scales" (mawāzīn) He means: the weight. The Arabs say: "With me you have a dirham equal to the scale (mīzān) of your dirham" and "equal to the weight of your dirham," and they say: "My house is equal to the scale (mīzān) of your house and the weight of your house" — by which is meant: opposite your house. The poet has said:
Before our meeting I was a man of strength, with every adversary I had his scale (mīzān) at hand.
By his words "with every adversary his scale" he means: his word with which he refutes the argument of the adversary. And Mujāhid used to say: "There is no scale — it is only a likeness that is set forth."