962 B
General Information:
This is the beginning of the Son of Man's message to the angel of the church in Philadelphia.
the angel
Possible meanings are that this "angel" is 1) a heavenly angel who protects this church or 2) a human messenger to the church, either a messenger who went from John to the church or the leader of the church. See how you translated "angel" in Revelation 1:20.
Philadelphia
This is the name of a city in the western part of Asia that today is modern Turkey. See how you translated this in Revelation 1:11. (See: rc://en/ta/man/translate/translate-names)
key of David
Jesus speaks of his authority to decide who may go into his kingdom as if it were King David's key. (See: rc://en/ta/man/translate/writing-symlanguage)
he opens and no one shuts
"he opens the door to the kingdom and no one can close it"
he shuts and no one can open
"he closes the door and no one can open it"