Rabbi Yohanan and Resh Lakish — the sage and the former bandit — formed one of the most famous study partnerships in the Talmud. Their relationship began in the most unlikely way: Rabbi Yohanan, who was extraordinarily beautiful, was bathing in the Jordan River when Resh Lakish, then a notorious gladiator and outlaw, leaped into the water after him.
"Your strength should be devoted to Torah," Rabbi Yohanan told him. Resh Lakish replied: "Your beauty should belong to women." Rabbi Yohanan made him an offer: "If you devote yourself to Torah study, I will give you my sister in marriage — and she is even more beautiful than I am."
Resh Lakish agreed. He tried to leap back out of the river to retrieve his weapons — but found he could not. The moment he committed himself to Torah, his physical strength diminished. The bandit's power was gone. What replaced it was far greater.
Resh Lakish became one of the sharpest minds in the Talmud, Rabbi Yohanan's constant intellectual sparring partner. Their debates were ferocious, brilliant, and essential to the development of Jewish law. The Talmud (Bava Metzia 84a) makes clear that Rabbi Yohanan valued Resh Lakish's challenges above all others — because only someone who had lived outside the law could truly test the law's boundaries.
When Resh Lakish died, Rabbi Yohanan was inconsolable. They sent him another study partner, but the new man simply agreed with everything Rabbi Yohanan said. "You are nothing like Resh Lakish," Rabbi Yohanan wept. "He would raise twenty-four objections, and I would give twenty-four answers, and the law was clarified. You just agree." Agreement without challenge is not partnership. It is loneliness.