@ Kiddo.......This is the field of self-knowledge. Vasistha gave answer to Rama's question in silence and said, "Silence was the only answer." What do you understood from this? The question which Rama asked was not an ordinary question. It was regarding Self-knowledge. Self which is beyond any duality cannot be comprehended by mind, senses, and intellect. So, Vasistha had to adopt a technique where it transcended all these duality. The moment we utter a word, it means there is a speaker, a listener, and a medium through which the sound is traveling. So, Vasistha's only option was to adopt a technique where there is no speaker and no listener. When there is no experiencer and no experienced, what remains? If you can understand this, you will understand what Vasistha's "Silence" was about.