Bede — on Rev 8:7 (Commentary on Revelation)

“And all green grass was burned up. All flesh is grass (Isaiah 40), which now, fattened with the softness of luxury, loses the flower of beauty under the burning sun of judgment, and, as the Lord says, today it is in the field and tomorrow is thrown into the oven (Matthew 6). Tyconius says about the third part in this place. He calls the third part the internal enemies. However, anything outside the Church is called the third part, and the Church is the third part, which fights against the double evil.”