Hero does not exhaust to commit to a quest

By wlk, in Rules questions & answers

Just wanted to share a recent clarification regarding readiness requirement for questing, which makes sense thematically, but didn't sound that obvious to me:

Q: Glorfindel with Light of Valinor attached "does not exhaust to commit to a quest".
Also Gandalf (OHauH) "does not exhaust to commit to a quest".
But can I still commit them to a quest if they are already exhausted ?
In other words, do I need characters to be ready to be able to commit them to a quest ?

A: You cannot commit an exhausted character to a quest. Both Glorfindel and Gandalf must be ready in order to commit to the quest.

Yeah, I remember having a long discussion with guys on my forum with the Watcher of the Bruinen...

I end up with the same kind of official answer.