Bursting smite

The next time you hit a creature with a melee weapon attack during the spell’s duration, your weapon flares with white-hot intensity, and the attack deals an extra 1d8 radiant damage to the target and any other creatures in a 15 foot cone or line. Enemies in the cone/line other than the initial target make a constitution save and take half damage if they succeed. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the initial extra damage dealt by the attack increases by 1d8 for each slot.