1 Peter 1:24

"For all flesh is as grass, and all the glory of man as the flower of grass. The grass withers, and the flower of it falls down; but the word of the Lord remains forever."

1 John 2:17

Now the world passes away, and the lust of it; be he who does the will of God, abides forever.

Treasury of Scripture Knowledge

Summary

But the rich, in that he is made low: because as the flower of the grass he shall pass away.

Bible References

Because

1 Peter 1:24
"For all flesh is as grass, and all the glory of man as the flower of grass. The grass withers, and the flower of it falls down; but the word of the Lord remains forever."
1 John 2:17
Now the world passes away, and the lust of it; be he who does the will of God, abides forever.