"Strange thought just came from Isaiah 40:6, the call to 'cry' came before there was any word as to what cry was made.  The message is not given until the messenger is responsive to the command... so today one never knows the specific 'what' or 'where' until he has said the general 'yes'."

~ Jim Elliot "The Journals of Jim Elliot"

"And the glory of the Lord shall be revealed, and all flesh shall see it together:

for the mouth of the Lord hath spoken it. 

The voice said, Cry.

And he said, What shall I cry?

All flesh is grass, and all the godliness thereof is as the flower of the field: the grass withereth, the flower fadeth: because the spirit of the Lord bloweth upon it: surely the people is grass.  The grass withereth, the flower fadeth: but the Word of our God shall stand for ever."

~ Isaiah 40:5-8