قسطاس

Etymology
Via an  term retained in 🇨🇬 and other Syriac spellings from, which also passed into 🇨🇬. For the stem ending in, maybe also denoting the occupation after ,. Influenced by.

Noun

 * 1)  weigher, moneychanger

Usage notes
After antiquity, when the word was no more understood, occurrences such as in the Qurʾān were frequently interpreted as “balance, scales”, and reused as such in few book titles and technical texts – e.g. the 1121 work of, surely not abiding by living language – including the particular phrasing  from 26:182.