The plague of boils

Exodus 9:1-12
The Lord said to Moses,"Go to Pharaoh and say to him, 'This is what the Lord says:...All the livestock of the Egyptians died, nut not one animal belonging to the Israelites died." Pharaoh sent men to investigate and found that none even one of the animals of the Israelites had died.
The plague of boils: Moses tossed soot from a furnace and stood  before Pharaoh, and festering boils(癤潰爛) broke out on men and animals. The magicians could not stand before Moses because of the boils that were on them and on all the Egyptians.
Why?
Disease strikes the cattle, and skin infections break out on humans and beasts, carried by the frogs and insects.
The hardness of Pharaoh's heart: God lets him be, lets him have his own way - so that in the end God's power is plain for all to see.
Moses could do it before Pharaoh and say to him what the Lord says.
Livestock died but not the people so Pharaoh did not care it.
It is severe that The magicians could not stand before Moses because of the boils. They were stood beside Pharaoh.
Their are different destination who belongs to the Lord and not belongs to the Lord.
How?
The life and disease are under control of God.