'To tread the wine-press,' as in Revelation 14:20, signifies exploring or examining the quality of works. In this case, they result from the doctrine of faith of the church. 'To tread the wine-press' signifies exploring, and the grape clusters signify works. All exploration or examination of church doctrine is made by the divine truth of the Word, which is not in that doctrine, but outside of it. This is why the wine press was trodden outside the city. 'To tread the wine-press' not only signifies exploring evil works, but also bearing with them in others, removing and casting them into hell, in Isaiah 63:1-3, Lamentations 1:15, and Revelation 19:15

(References: Apocalypse Revealed 652; Lamentations 1)