Ke'an always means "now". Onkelos usually translates "na" *not* as "please" but as "now". When Rashi says "ein na ela leshon bakasha" he may mean that *this instance* of "na" means "please" but generally it means "now". -- Zev Sero A prosperous and healthy 5780 to all zev at sero.name Seek Jerusalem's peace; may all who love you prosper