The Sages once captured the yetzer hara (יצר הרע)—the evil inclination itself. According to Yoma 69b, they prayed for three days, and it was delivered into their hands. A fiery lion cub emerged from the Holy of Holies. The prophet Zechariah confirmed: this is it.
They seized it. They imprisoned it. For three days, the evil inclination was locked away.
Then reality set in. Someone went looking for a fresh egg in all of the Land of Israel. Not a single one could be found. Without the evil inclination, no creature had any desire—not even chickens. No mating. No reproduction. No eggs.
The Sages faced an impossible dilemma. They could not destroy the yetzer hara without destroying the world's capacity to function. They asked: can we at least blind it, diminishing its power without killing it? They blinded it, and the result was a partial victory—the inclination toward the most extreme transgressions was weakened, but basic desire continued.
The backstory involves the verse in Nehemiah: "And Ezra blessed the Lord, the great God" (Nehemiah 8:6). What made God "great" in this context? According to one explanation, Ezra used God's explicit Name—the Shem HaMeforash (שם המפורש). According to another, he established the formula recited at the end of every blessing: "Blessed be the Lord, God of Israel, from eternity to eternity."
The capture of the evil inclination was part of the same era of spiritual boldness. The Men of the Great Assembly cried out: "It is this evil inclination that destroyed the Temple, burned the Sanctuary, killed the righteous, and exiled Israel. And it still dances among us!" They dared to restrain it. And they learned the cost: a world without desire is a world that cannot sustain life.