Oecumenius — on Rev 1:4 (Commentary on Revelation)

“The seven spirits are seven angels; not as equals or coeternal, associated with the Holy Trinity, but as genuine ministers and faithful servants. For the prophet says to God, "For all things are your servants." (Ps. 118:91) And among all, the angels are included. And again, he says concerning them: Bless the Lord, all his powers, his ministers doing his will. (Ps. 102:21) In this form, the apostle also corresponded with Timothy by writing the first Epistle; "I seriously charge you," Paul says, "before God and Jesus Christ and the elect angels." (1 Tim. 5:21) But also in what is said "before His throne," He attested to them a domestic [οἰκετικὴν] and liturgical [λειτουργικὴν] order; however, not equality in rank.”