Then one of the four living creatures gave the seven angels seven golden bowls full of the wrath of God, who lives forever and ever.
Observe, I. How these angels appeared - coming out of heaven to execute their commission: The temple of the tabernacle of the testimony in heaven was opened, Rev 15:5. Here is an allusion to the holiest of all the tabernacle and temple, where was the mercy-seat, covering the ark of the testimony, where the high priest made intercession, and God communed with his people, and heard their prayers.
Commenting on Revelation 15:5-8
And one of the four beasts,.... Or living creatures: now we hear of them, as of the four and twenty elders, under the blowing of the seventh trumpet, Rev 11:16 with which this vision is contemporary; these living creatures are the ministers of the Gospel; See Gill on Rev 4:6 and this was one, or the first of them, who was like a lion, for...
Verse 7. And one of the four beasts. . Which one of the four is not mentioned. From the explanation given of the design of the representation of the "four beasts," or living creatures, in Barnes on "Re 4:6-7", it would seem that the meaning here is, that the great principles of that Divine government would be illustrated in the events which are now to occur.