Nahum ish Gamzo — called that because no matter what happened, he always said "Gam zu le-tovah" ("This too is for the best") — was sent by the Jewish community to the Roman Emperor carrying a chest full of precious gems as tribute.
He stopped at an inn along the way. During the night, the innkeepers crept into his room, opened the chest, stole every jewel, and filled it with ordinary dust. Nahum did not discover the theft until he stood before the Emperor himself and opened the chest.
The court erupted in laughter. The Jews had sent dirt as a gift to Rome? The Emperor, humiliated and furious, prepared to execute Nahum on the spot.
At that moment, the prophet Elijah appeared disguised as one of the Roman courtiers. He leaned toward the Emperor and whispered: "Perhaps this is the miraculous dust of Abraham. The patriarch had dust that turned into swords and arrows when thrown at his enemies."
The Emperor, intrigued, sent the dust to a battlefield where his legions had been besieging a city for three years without success. Soldiers hurled the dust at the walls. It turned into a storm of arrows and the city fell immediately.
The Emperor rewarded Nahum lavishly and sent him home laden with treasure. When the thieving innkeepers heard the story, they demolished their own building, gathered the rubble, and brought it to the Emperor, claiming it was the same miraculous dust. The Emperor tested it. Nothing happened. The innkeepers were executed. The Talmud in Sanhedrin (108b-109b) and Taanit (21a) preserves this as the quintessential tale of divine providence — gam zu le-tovah.