Destructive Smite

The next time you hit a creature with a weapon attack before this spell ends, the weapon pulses with arcane energy strike. The attack deals an extra 3d6 thunder damage to the target, which must succeed on a Constitution saving throw or be knocked prone.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the extra damage increases by 1d6 for each slot level above 3rd.