Albert Barnes Commentary Revelation 3:7

"And to the angel of the church in Philadelphia write: These things saith he that is holy, he that is true, he that hath the key of David, he that openeth and none shall shut, and that shutteth and none openeth:" — Revelation 3:7 (ASV)

And to the angel of the church in Philadelphia (Revelation 3:7). See Barnes' commentary on Revelation 1:20.

These things says he that is holy (Revelation 3:7). This refers undoubtedly to the Lord Jesus. The appellation holy, or the holy one, is one that befits him and is often given to him in the New Testament (Luke 1:35; Acts 2:27; Acts 3:14).

It is not only an appellation appropriate to the Savior, but also well adapted to be employed when he is addressing the churches. Our impression of what is said to us will often depend greatly on our idea of the character of him who addresses us, and solemnity and thoughtfulness are always fitting for us when we are addressed by a holy Redeemer.

He that is true (Revelation 3:7). This is another characteristic of the Savior well fitted to be referred to when he addresses men. It is a characteristic often ascribed to him in the New Testament (John 1:9, 14, 17; John 8:40, 45; John 14:6; John 18:37; 1 John 5:20) and one which is eminently adapted to impress the mind with solemn thought, considering that he is to pronounce on our character and determine our destiny.

He that has the key of David (Revelation 3:7). This expression is manifestly taken from Isaiah 22:22: And the key of the house of David will I lay upon his shoulder. As used by Isaiah, the phrase is applied to Eliakim, and it should not be inferred that because this language is applied to the Lord Jesus here, it originally had such a reference. "The application of the same terms," says Professor Alexander on Isaiah 22:22, "to Peter (Matthew 16:19) and to Christ himself (Revelation 3:7) does not prove that they here refer to either, or that Eliakim was a type of Christ, but merely that the same words admit of different applications."

The language is that which properly denotes authority or control—as when one has the key of a house and has unlimited access to it. The meaning here is that, as David is represented as the king of Israel residing in a palace, so he who had the key to that palace had regal authority.

He that opens, and no man shuts, etc. (Revelation 3:7). He has free and unrestrained access to the house: the power of admitting anyone or of excluding anyone. Applied here to the Savior, as king in Zion, this means that in his kingdom he has absolute control regarding the admission or exclusion of anyone. He can prescribe the terms; he can invite whom he chooses; he can exclude those whom he judges should not be admitted. A reference to this absolute control was entirely proper when he was addressing a church and is entirely proper for us to reflect on when we think of the subject of our personal salvation.