You stomp a foot on the ground, and the resulting shock wave hurls your enemies away.

Encounter   ✦     Arcane, Implement, Thunder
Standard Action      Close burst 3

Target: Each enemy in the burst

Attack: Charisma vs. Fortitude

Hit: 3d6 + Charisma modifier thunder damage, and you push the target a number of squares equal to your Charisma modifier and knock it prone.

Published in Player's Handbook 2, page(s) 147.