Booming Buckler

You sheath your shield in booming energy to punish attackers. For the duration, whenever a creature makes a melee attack against you and misses, the creature must succeed on a Constitution saving throw or take 2d6 thunder damage and be pushed 10 feet away from you. On a successful save, the creature takes half as much damage and isn't pushed.

In addition, when you shove a creature to push it away from you, you can push it an additional 10 feet away from you. The spell ends early if you drop the shield.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 for each slot level above 2nd.