ق س ط سq-s-ṭ-s
quadriliteral — قِسْطَاسqisṭās / قُسْطَاسqusṭās: balance, the instrument by which things are weighed justly. The majority of the lexicographers hold it to be of Greek (Rūmī) origin, معرّبmuʿarrab; some have said it is derived from q-s-ṭ (justice). The qualification «الْمُسْتَقِيْمal-mustaqīm» indicates its genuineness and accuracy. Twice in the Quran, both times in this same construction: ﴿وَزِنُوْا بِالْقِسْطَاسِ الْمُسْتَقِيْمِ﴾ (Al-Isrāʾ 17:35, Ash-Shuʿarāʾ 26:182).