Sankat Mochan Mahabali Hanuman S01 E138 Pashanasur Ka Ant

Hanuman reaches Shani Grah so that he can free Shanidev but Pashanasur tries to lure him into his trap after which he intends to kill Hanuman. Shanidev, after analysing the situation gives Hanuman a very important advice. What is this advice? Why is Ravan standing in front of Hanuman?