Isaiah
Isaiah 40:6ESV·traditional attribution

A voice says, “Cry!” And I said, “What shall I cry?” All flesh is grass, and all its beauty is like the flower of the field.

John Calvin Reformed @genevareformer

6. The voice said, Cry. He now describes a different “voice” from that of which he formerly spoke; for hitherto he had spoken about the “voice” of the prophets, but now he means the “voice” of God himself commanding the prophets to cry.

Matthew Henry Presbyterian @wholebiblehenry

The time to favour Zion, yea, the set time, having come, the people of God must be prepared, by repentance and faith, for the favours designed them; and, in order to call them to both these, we have here the voice of one crying in the wilderness, which may be applied to those prophets who were with the captives in their wilderness-state, and who, when...

Commenting on Isaiah 40:3-8

John Gill Reformed Baptist @doctorgill

The voice said, cry,.... Not the same voice as in Isa 40:3, nor the voice of an angel, as Aben Ezra; but a voice from the Lord, as Jarchi; the voice of prophecy, says Kimchi; it is the Lord's voice to the prophet, or rather to any and every Gospel minister, giving them an order to prophesy and preach, without which they cannot preach regularly...