Satan makes plans from Hell - The Incarnation - Bk 1 - Ch 10

At the conclusion of the events outlined in Revelations 12, Satan and demons held a council in hell. During the council, all forms of sin and depravity were decided upon. They came to the conclusion that the greatest vengeance and injury against God would be to impede the effects of His love, which they knew God bore toward mankind.

Satan asked to be able to tempt and afflict Christ and the Blessed Virgin Mary. God allowed it, but He also confirmed that Satan could have no part in Mary and that he was not allowed to harm her physically. God told Satan that Christ would defeat his temptations as an example for the faithful. Satan, knowing that he would fail in his attempts at Mary, turned his focus to the rest of us. The full conversation was witnessed by the Venerable Sister Mary of Ágreda and reproduced here.