"You don't need to worry about anything. You'll be safe, I promise you,"
Those were the words of assurance he gave to Lily the night before when she had explained about being watched by something she couldn't see. Not only her though because David was included. He had told her that because he knew just what was going on with her. The exact thing that he couldn't even utter to her.
The look she had given him after he had said that showed that she was a bit suspicious of him. He had said those words as a hint that he knew what exactly she was going through, and that was how he wanted it to be. If she thought that way, then it would make her feel safer whenever she ws experiencing that feeling.