Albert Barnes Commentary Revelation 4:9

"And when the living creatures shall give glory and honor and thanks to him that sitteth on the throne, to him that liveth for ever and ever," — Revelation 4:9 (ASV)

And when those beasts give glory, etc. As often as those living beings ascribe glory to God. They did this continually (Revelation 4:8), and, if the above explanation is correct, then the idea is that the ways and acts of God in His providential government are continually of such a nature as to honor him.