FWIW I side with the "perpetual" (or one of various approximate synonyms) faction that cites the Syriac translation from Aramic. I think that, firstly, it makes sense to see "always-being" as a kind of superlative of mere "being". And secondly, it seems plausible that one might arrive from "always-being" via "being-at-all-days" or "being-everyday" to the common "daily" translation.