Shutting the gates of Jerusalem as the dark comes on is the closing of the openings of the head, the senses through which the outer world pours in, so that the inner city of peace can keep its rest undisturbed. The sabbath is the state of inward stillness, the ceasing of labor where a person rests in the deeper self, and no burden may be carried in because any traffic of the senses would break that quiet and load the mind down again.
The servants posted at each gate are the disciplined faculties set to guard the entries, the watchful attention stationed at eye and ear to refuse the loads of thought and craving that would enter. Jerusalem is the seat of peace within the head, and its gates are barred at the hour of rest so the inner sabbath is kept whole, the city sealed against the outer world while the self dwells in its own stillness.
Gates of Jerusalem: the openings of the head, the senses through which the outer world enters the inner city
Jerusalem: the seat of peace within the head, the inner city guarded and kept at rest
Sabbath: the state of inward stillness where a person ceases labor and rests in the deeper self
Servants at the gates: the disciplined faculties posted at the senses to refuse the burdens that would enter
Burden: the load of sense and craving that would be carried into the mind and break its rest