التفسير التبليغي
(وَأَقِيمُوا الْوَزْنَ بِالْقِسْطِ وَلا تُخْسِرُوا الْمِيزَانَ) (9)
And establish the weighing with justice, meaning: be just in weighing, and (وَلا تُخْسِرُوا الْمِيزَانَ) meaning: do not diminish people's rights in weighing.
(وَأَقِيمُوا الْوَزْنَ بِالْقِسْطِ) meaning: steadfastness in the path, and adherence to the limit of virtue.
And establish the weighing, meaning: establish the tongue with speech.
And do not diminish the balance, meaning: do not speak without right.
The first weighing is the weighing of speech, which is the essence of clear expression. If it is diminished, all other balances after it are diminished.
And do not diminish the balance - this is a repetition for emphasis in the recommendation.
Some wise men said: Justice is Allah Almighty's balance, which He set for creation and established for truth.
Source: التفسير التبليغي