The elder warned us not to pray while our hearts were steeped in unprayerful feelings, without thoughts wandering as they chose. Prayer is not a mechanical activity, but a confrontation, a conversation with the Holy Presence. Pray humbly, then, in awe of God.
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.