Enervate

You cause a wave of lethargy to drain a creature of energy. Target creature must succeed on a Constitution saving throw or gain a point of exhaustion and their strength score is reduced by 1. The target dies if this reduces its Strength to 0. Otherwise, the reduction lasts until the target finishes a short or long rest.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the strength reduction is increased by 1 for every two slot levels above 3rd.