The temple is the dwelling place of God and so stands for God’s presence (see Revelation 3:12; Revelation 7:15; Revelation 11:19; also Revelation 21:22). That this angel came from the temple indicates, then, that he came from very God’s presence (see also Revelation 5:11) and thus speaks a word that comes directly from God himself.
15 And another angel came out of the temple, calling with a loud voice to him who sat on the cloud, “Put in your sickle, and reap, for the hour to reap has come, for the harvest of the earth is fully ripe.”