Thunderstaff is a daily power available to Wizards at 5th level[Dr380]
Thunderstaff
Wizard Attack 5
As your enemy comes too close, you slam the butt of your staff into the ground, sending a shockwave that knocks it off its feet and far away from you
Daily ✦ arcane, implement, thunder
Melee 2
Requirement: You must be wielding a staff.
Trigger: An enemy moves to within 2 squares of you
Target: The triggering enemy
Attack: Intelligence vs. Fortitude
Hit: 2d6 + Intelligence modifier, and the targer is deafened and dazed until the end of your next turn.
Miss: Half Damage, and the target is deafened until the end of your next turn
Effect: You push the target 5 squares.