Question

Are the walls in rest or in motion?

Answer 1

Walls are at rest but only with respect to us. With respect to the Earth it is under motion.  Earth is under motion [Rotation and Revolution] thus all the things [Living and Non-Living] on Earth is under motion

Answer 2

To classify any object as moving or static, we need a reference point in reference to which the state is to be decided. Here, as the question doesn't mention any reference point, the most standard answer  would be either motion or rest, depending on the reference object.