A.T. Robertson Commentary Revelation 16:1

"And I heard a great voice out of the temple, saying to the seven angels, Go ye, and pour out the seven bowls of the wrath of God into the earth." — Revelation 16:1 (ASV)

A great voice (μεγαλης φωνης). Not an angel as in 5:2; 7:2; 10:3; 14:7,9,15,18, but of God as 15:8 shows, since no one could enter the ναος.

Pour out (εκχεετε). Second aorist active imperative of εκχεω (same form as present active imperative). Blass would change to εκχεατε (clearly aorist) as in verse 6.

The seven bowls (τας επτα φιαλας). The article points to verse 7.