Rabbi Eliezer ben Hyrcanus was one of the greatest sages of his generation, a man whose knowledge of Torah was said to be like a plastered cistern that never lost a drop. Yet even he once found himself in trouble with the Roman authorities.
The Talmud (Avodah Zarah 16b) records that Rabbi Eliezer was once arrested by the Romans on suspicion of heresy. He was brought before a Roman governor who could not believe that a man of such learning would entertain forbidden teachings. "How can a sage like you occupy himself with such idle matters?" the governor asked.
Rabbi Eliezer replied cryptically: "I trust the Judge to judge truly." The governor, thinking this referred to him, released the sage. But Rabbi Eliezer had meant the Judge above — God Himself.
Afterward, Rabbi Eliezer was deeply troubled. He searched his memory to understand why God had allowed him to be arrested. His student Rabbi Akiba came to him and asked: "Perhaps some teaching of a heretic once pleased you, and you did not reject it strongly enough?"
Rabbi Eliezer remembered. Once, while walking in the upper marketplace of Tzippori, he had encountered a man who shared a novel interpretation of a Torah verse. The teaching had delighted him. That moment of pleasure in a heretic's words — that was the sin. From then on, Rabbi Eliezer guarded himself fiercely against any teaching that did not come from a recognized master of Torah.