all(?) the healings in the first four books of the Bible

 Genesis 20:17 - God heals abimelech and his family, after God has made them all impotent.

Exodus - God heals Moses of leprosy after God strikes him with leprosy.

Leviticus - God heals Miriam of leprosy after God strikes her with leprosy. 

Leviticus - God heals people of snake bites, when they look on a brass serpent Moses makes. God sends the snakes. 

There may be more healings, but mostly it looks like God stops killing people, but doesn't heal anywhere else.

Notice God makes them all ill, and then heals them.

Half of the healings are for Moses and his sister of the same disease.