"Il n'a point donc voulu mettre loy pour la posterité: mais seulement
remedier aux incommoditez presentes _par maniére de provision_ (comme
on dit)," &c.
The general import of the passage is, that Jethro's counsel to Moses, as to
the appointment of rulers over the people, was not intended to apply to
Canaan, but only to their sojourn in the wilderness.
I do not see how the "formula professionis monasticæ" helps us; unless,
indeed, "modus promissionis" were a kind of temporary and conditional vow,
which does not appear in Ducange.