Venomous Smite

The next time you hit a creature with a melee weapon attack during the spell’s duration, your weapon oozes a sickly green liquid, and the attack deals an extra 5d8 poison damage to the target and imparts magical poison into the target's blood. At the start of each of its turns until the spell ends, the target must make a Constitution saving throw. On a failed save, it takes 1d8 poison damage and becomes poisoned until the start of its next turn. On a successful save, the spell ends.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the initial extra damage dealt by the attack increases by 1d8 for each slot level above 4th.