Revelation 10:7; Revelation 14:6

Revelation 10:7

7 but in the days of the voice of the seventh angel, when he is about to sound, then the mystery of God is finished, as He preached to His servants the prophets.

Revelation 14:6

6 And I saw another angel flying in midheaven, having an eternal gospel to preach to those who live on the earth, and to every nation and tribe and tongue and people;