The number 7 symbolizes completion and the full round of the spiritual centers, and its double weight here, the seventh day and the seventh circuit, marks the point where a discipline held faithfully through its whole cycle finally breaks the wall it circled. The city is the fortified structure of resistance within, the old ego-fortress of habit and belief that no single push can topple, only the patient, repeated turning of attention around it until the barrier gives way. Rising at dawn is the awareness lifting into its clearest state before the work.
The walls that fall are the inner defenses a person built to keep the lower self intact, undone at last not by force but by the completed round. The plain sense is that steady inner work, carried all the way through its full cycle, brings down a resistance that force alone never could.
Seventh day and 7 times: the number 7 as completion and the full round of the spiritual centers, the whole cycle carried through
City: the fortified structure of resistance within, the ego-fortress of habit and belief
Walls: the inner defenses a person built to keep the lower self intact