Also known as the angel of adversity, his role is similar to that of SATAN, as an enemy of God and tempter of humankind.
Mastema is called the "Father of Evil." He appears in the pseudepigraphal Book of Jubilees, the Zadokite Fragments and the Dead Sea Scrolls. Noah had prayed for God to imprison all evil spirits. At Mastema's behest though, God granted the angel one-tenth of all demons to be committed to his service. Thus, Mastema roams about testing the faith of human souls.
Mastema is also known for helping Egyptian sorcerers against Moses and Aaron, and is said to be the one who attempts to kill Moses in Exodus 4:24.