PHB
False Life
1-level Necromancy
Casting Time: 1 action
Range/Area: Self
Components: V, S, M
Materials: a small amount of alcohol or distilled spirits
Duration: 1 hour
Bolstering yourself with a necromantic facsimile of life, you gain 1d4 + 4 temporary hit points for the duration.
At higher levels: When you cast this spell using a spell slot of 2nd level or higher, you gain 5 additional temporary hit points for each slot level above 1st.