Question: There is no concept of prison in Kabbalah, but there is a concept of the death penalty. Should a person have a reason to be afraid of harming other members of society?
Answer: No. The death penalty is merely a theoretical concept, and in fact, practically no one was ever executed in the nation of Israel.
During its entire existence, the Sanhedrin (the Supreme Court) sentenced someone to death only once, and as far as I know, this was later canceled. It was considered that they can sentence a person to death only once every 70 years! The death penalty was regarded as something inhumane and terrible.
From KabTV’s “Fundamentals of Kabbalah” 7/7/19