Jericho, the moon-city, is the fortified stronghold of the lower psychic and emotional nature, walled against the entry of higher consciousness. The wall is the barrier of resistance a person builds around old habits, and it does not fall to force but to sound. The trumpet is the inner vibration, the raised tone of concentrated spiritual energy sustained by the priestly centers of the body until the frequency of the wall itself breaks. Vibration meets vibration, and the barrier collapses.
Going up into the city, every man straight before him, is the awakened energy rising through the awakened body along its own true line, each force moving directly upward without wandering. The stronghold that seemed impassable dissolves the moment the correct inner sound is held long enough. What guards the lower self is undone by the higher vibration a person learns to raise from within.
Jericho: the moon-city, the fortified stronghold of the lower emotional and psychic nature
Wall: the barrier of resistance built around old habits, guarding the lower self
Trumpet: the inner vibration of concentrated spiritual sound that breaks the barrier by frequency
Priests: the higher centers of the body that sustain the raising tone