Philadelphia is the head, the last and highest of the 7 body centers, the pineal and ajna where the risen force finally arrives. What speaks to it holds the key of David, and that key is a progression through the mind: Adam, then David, then the Messiah, 3 stages of consciousness carried from the Kabbalah, the growth of a person from raw earthly beginning to the anointed state at the crown.
Whoever reaches that stage opens what no one below can open and closes what no one below can force. The authority belongs to the summit of the inner ladder, because only the awakened head can unseal or seal the centers beneath it.
Philadelphia: the head, the pineal and ajna center, the highest of the 7 body centers
Key of David: the progression of Adam, David, and the Messiah, the 3 stages of consciousness rising in the mind