By: Albus Dumbledore

Ithink this means that words in my not so humble opinion  mean that maybe it’s not so nice what I’m thinking in my opinion, or it means that you say your  opinion that’s not so nice out loud and hurts someone’s feelings.

Also I think that  the part were it says in our most inexhaustible source of magic maybe means that you say in in an exhausted way and that it is the exhausted source of thee magic which is energy in side of you.