Rabbi Hanina ben Dosa was deep in prayer, standing perfectly still, his eyes closed, his lips moving in silent communion with God. He did not notice the venomous adder that had slithered out from beneath a pile of stones and was winding its way toward his bare foot.
The snake struck. Its fangs sank into Rabbi Hanina's heel. But the sage did not flinch, did not cry out, did not interrupt his prayer by so much as a syllable. He continued his supplication as though nothing had happened.
The people standing nearby watched in horror, expecting the rabbi to collapse at any moment. Adder venom was lethal. A grown man could die within the hour. But Rabbi Hanina prayed on, minute after minute, undisturbed.
When he finally concluded his prayers and opened his eyes, the onlookers rushed to examine the bite. The wound was there, but the skin showed no swelling, no discoloration. Rabbi Hanina felt no pain. Then someone noticed the adder lying a few paces away. It was dead.
"It is not the adder that kills," the people began to say throughout the land of Israel. "It is sin that kills." Rabbi Hanina's purity of heart and the intensity of his prayer had rendered the venom powerless. The snake, having bitten a man whose soul was entirely directed toward Heaven, had destroyed itself.
The Talmud in Berakhot (33a) preserves this tale as a testament to the protective power of genuine devotion. When a person stands before God with complete concentration, the dangers of the physical world lose their hold. The adder bit a body. But the prayer shielded the soul, and in the contest between venom and devotion, devotion won.