Albert Barnes Commentary Job 12:10

"In whose hand is the soul of every living thing, And the breath of all mankind?" — Job 12:10 (ASV)

In whose hand is the soul of every living thing – Margin, “Life.” The margin is the more correct rendering. The idea is that all are under God's control. He gives life, health, and happiness when He pleases, and when He chooses He takes them away. His sovereignty is manifested, says Job, in the inferior creation, or among the beasts of the field, the fishes of the sea, and the birds of heaven.

And the breath of all mankind – Margin, “Flesh of man.” The margin is in accordance with the Hebrew. The meaning is that humanity is subject to the same laws as the rest of creation. God is a sovereign, and the same great principles of His administration may be seen in all His works.