Silence is not merely negative -- a pause between words, a temporary cessation of speech -- but properly understood, it is highly positive: an attitude of attentive alertness, of vigilance, and above all, of listening.
It seems to me that a mountain is an image of the soul as it lifts itself up in contemplation. For in the same manner as the mountain towers above the valleys and lowlands at its foot, so does the soul of the one who prays mount into the higher regions up to God like an eagle taking wing.