This very Franciscan saying (not attributed to Francis, though) describes a problem I've had all my life--when is it "necessary" to use words and are they all that helpful anyway. Ham used to speculate that writing was something we did for ourselves, helping one to focus and clarify one's thoughts. As a family systems therapist, I think of words as filling the "space" between actions and an attempt to manipulate others. As a communications therapist, I think that words are like arrows shot into the void--at best accidentally hitting some "target". Given that Francis spent much of his time in contemplative solitude in rude hermitages, I bet he didn't center his life on words.
Yet, Francis is known even secularly for his writings--among the first extant ones in the "Italian" vernacular. He used words to preach to the birds and the wolf as well as the people. Perhaps his speech was simply an integrated part of his actions, an unconscious action like lifting one's feet when running.
I think I am uncomfortable with words because they often do not point to mystery. They often appear vain, pointing to my intellectual vanities rather than to the glory of God. This gets paradoxical again--speak without "speaking", simply revealing. Perhaps words are okay as long as they are art, pointing to the golden shekinah that expands from the icons to fill the temple. Yes, that seems to fit: when they reveal God's presence they are golden and when they reveal my emptiness they are drab.