Isaiah 40:6

⁴ Every valley shall be exalted, and every mountain and hill shall be made low: and the crooked shall be made straight, and the rough places plain:

⁵ 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 goodliness thereof is as the flower of the field:

⁷ The grass withereth, the flower fadeth: because the spirit of the LORD bloweth upon it: surely the people is grass.

⁸ The grass withereth, the flower fadeth: but the word of our God shall stand for ever.

Do read the surrounding verses too, because the context often says more than a single verse.

Compare

BSB: A voice says, “Cry out!” And I asked, “What should I cry out?” “All flesh is like grass, and all its glory like the flowers of the field.
KJV: The voice said, Cry. And he said, What shall I cry? All flesh is grass, and all the goodliness thereof is as the flower of the field:
WEB: The voice of one saying, “Cry out!” One said, “What shall I cry?” “All flesh is like grass, and all its glory is like the flower of the field.
ASV: The voice of one saying, Cry. And one said, What shall I cry? All flesh is grass, and all the goodliness thereof is as the flower of the field.
DARBY: A voice saith, Cry. And he saith, What shall I cry? All flesh is grass, and all the comeliness thereof as the flower of the field.
BLB: The voice of one saying: “Call out!” And he said, “What shall I call out?” “All flesh [is] grass, and all its loveliness [is] like the flower of the field.

ÅB: Hør! Det er en som sier: Rop! Og en annen svarer: Hva skal jeg rope? - Alt kjød er gress, og all dets herlighet som markens blomst.
OTB: En røst sier, "Rop ut." Og jeg sa, "Hva skal jeg rope?" Alt kjød er som gress, og all dets skjønnhet er som markens blomster.
B1930: Hør! Det er en som sier: Rop! Og en annen svarer: Hvad skal jeg rope? - Alt kjød er gress, og all dets herlighet som markens blomst.

Psalms 103:15–16
As for man, his days are as grass: as a flower of the field, so he flourisheth.
Read in context
1 Peter 1:24–25
For all flesh is as grass, and all the glory of man as the flower of grass. The grass withereth, and the flower thereof falleth away:
Read in context
Psalms 102:11
My days are like a shadow that declineth; and I am withered like grass.
Read in context
James 1:10–11
But the rich, in that he is made low: because as the flower of the grass he shall pass away.
Read in context
Job 14:2
He cometh forth like a flower, and is cut down: he fleeth also as a shadow, and continueth not.
Read in context
Isaiah 58:1
Cry aloud, spare not, lift up thy voice like a trumpet, and shew my people their transgression, and the house of Jacob their sins.
Read in context
Psalms 90:5–6
Thou carriest them away as with a flood; they are as a sleep: in the morning they are like grass which groweth up.
Read in context
Psalms 92:7
When the wicked spring as the grass, and when all the workers of iniquity do flourish; it is that they shall be destroyed for ever:
Read in context