relative or not?

Hello,

In a new translation of Erasmus’ Adagia, the subtitle ‘quibus ex rebus accedit novitas paroemiae’ is translated with ‘ce qui donne au proverbe son originalité’. It appears that quibus is considered a relative pronoun. But what is the antecedent, even unexpressed? Isn’t more logical to consider the whole sentence a question?

Thanks for your opinions!

quibus ex rebus = ex quibus rebus

It is indeed a question, but the French translation works fine, I think
Quaestio vera est at bona ista versio in gallicam, puto.