The voice said,
Cry.
And he said, What shall I cry?
All flesh is grass, and all its loveliness is as the flower of the field:
All Commentaries on Isaiah 40:6 Go To Isaiah 40
Eusebius of Caesarea
AD 339
This is the nature of all flesh and of the human who bears the image of the earthly; I mean the body-lover who lives according to the flesh. In like manner the grass of the earth and the beautiful flowers rise up and bloom for a short time, but soon they wither through their unstable nature.… The voice in the desert prophesying about God the Word is John teaching about Christ, as only from then on will it stand forever, and it guards those who stand with it and run with it as those who are becoming models of its salvation.