Revelation 3:7

And to the angel of the church in Philadelphia write: See Poole on "Revelation 1:20", See Poole on "Revelation 2:1". Of this Philadelphia we read no more in holy writ. We are told there were three cities of that name, one in Egypt, one in Syria, another in Phrygia, or in Mysia or Lydia, which is that here intended. These things saith he that is holy; that is, the Holy One, Acts 3:14. He that is true; true to his word of promise or threatening. He that hath the key of David; that is, the key of the house of David, mentioned Isaiah 22:22; the key of the church, which answered the temple, the house David designed for God: the use of the key is to open and shut, or make fast. He that openeth, and no man shutteth; and shutteth, and no man openeth; who admits into the kingdom of heaven whom he pleaseth, and none can hinder him, and shutteth out of heaven whom he pleaseth. The house of David typified the church, the church containeth the number of those that shall be saved; Christ is here described as he who hath the sole and absolute power of saving and condemning whom he pleaseth.