Was it God, the devil, or free will that guided his hand and stayed his temper?
God made man
God made the "devil"
God granted free choice..
Whether the man was motivated by Devil, or himself, or God, it's all the same thing, but since God gave us free choice, ultimately it was his choices alone with God's gift that led him to kill his Mother.. Good and Evil both being the creation of the same deity cannot be distinguished from one deity to a sub deity to ones self.. it's just the way it is.. and it's a waste of time trying to decide "what" motivated him except by saying he and he alone made the choices he made.