I speak from slight experience here... Make sure the temps are really good and don't waver too much and then cover the tank all around for added privacy and leave him totally alone for a week (except for spot cleaning or water changes, but even then don't touch the hide he's in). No feedings or anything.

Rescues, especially those coming from bad husbandry situations, really need to be left alone to realize that their new home is safe and comfortable. And don't worry about him apparently not moving around; he's probably doing it when it's really dark and quiet. My little rescue seemed to not move from the cool side of his tank for the first 5 or 6 days I had him here, but once I did catch him slipping back over from the warm side when I peeked over the blanket to check temps.

Just leave him in a nice, quiet place with good cover and steady temps/humidity and he should be fine for feeding and MINIMAL handling after a week or so. And Kudos to you for helping him out!