Originally posted by: proteeti
I don't think this incident occurred in the main Ramayan (did it?).
As far as the story goes, I think this was to show Rama's dedication to his praja-jan, a prelude to what he would go on to do with Seeta. A kind of a "the praja is always right" kind of mentality.
Also, this was at the end of Treta yug, and slowly the vices of Dwapara were engulfing the people: a fine manifestation of which was the steady solidification of the birth-based caste system.
the Brahman was:
-> top caste
-> guest of Rama
-> shraap dene waale,
I guess a mixture of these teasons made Rama do that.
That means satisfying the Subjects of his kingdom and brahmins of his kingdom were topmost duty of Lord Rama.