Edward Plaisance Jr Dec 14, 2012:

thanks for the idiom... I saw that in the dictionary but it didn't give the explanation you did...good to know that...thanks

Alireza Amini Dec 13, 2012:

Dear Edward You are right That's why I said take mouthpiece into consideration which means spokesman. In Farsi, specially in informal usage, we call such a person وکیل وصی a person who speaks in fovour of you and mostly criticised by others because of that....for example it is common to say...مگه وکیل وصیش هستی بزار خودش حرف بزنه

Edward Plaisance Jr Dec 13, 2012:

Aaron... he was the older brother of Moses and is considered to be the first high priest of the Hebrews...he was also Moses' spokesman...so this is the connection here...Aaron=spokesman/representative

Hojat Borumandi Dec 13, 2012:

perhaps it has been used to refer to a talkative person

Alireza Amini Dec 13, 2012:

Note Please notice...It is used figuratively here....take mouthpiece into consideration it helps you get the meaning...