Hellish rebuke V S

You point your finger, and the creature that damaged
you is momentarily surrounded by hellish flames.
The creature must make a Dexterity saving throw.
It takes 2d10 fire damage on a failed save, or half
as much damage on a successful one.
At Higher Levels. When you cast this spell using a
spell slot o f 2nd level or higher, the damage
increases by 1dlO for each slot level above 1st.