Thunder Palm

A concussive blast resounds when you clap your hand upon an enemy. Make a melee touch attack. On a hit, the target takes 1d8 thunder damage. A medium or smaller creature is pushed 5 feet away from you.

This spell's damage increases by 1d8 when you reach 5th level (2d8) 11th level (3d8) , and 17th level (4d8).