Adam Clarke on Revelation 7:2

The seal of the living God - This angel is represented as the chancellor of the supreme King, and as ascending from the east, απο ανατολης ἡλιου, from the rising of the sun. Some understand this of Christ, who is called ανατολη, the east, Luk 1:78.

Four angels, to whom it was given to hurt - Particular agents employed by Divine providence in the management of the affairs of the earth; but whether spiritual or material we know not.