Gaster's exemplum No. 273 preserves two short Talmudic stories about how seriously the sages took small signs.
In the first, Rav — the third-century Babylonian sage who founded the academy at Sura — refused to eat meat that had been brought to him on a boat, even though he had personally kept his eye on the package the whole time and there had been no moment in which it could have been substituted. His colleagues were puzzled. He had watched it. What was the problem?
Rav's reasoning was stricter than the letter of the law. Meat that leaves the Jewish community's sight, even for a moment, raises a question that should not be answered by the eye alone. The Torah's system of kashrut, Rav believed, is not a background of vague confidence; it is a forest of small fences, and the pious Jew builds more fences than the law strictly requires. Watching with your own eyes is not always enough; you also have to watch for what you cannot see.
In the second story, Rabbi Yochanan — the towering Land-of-Israel sage of the same era — heard a child reciting a verse of Scripture. It was the casual chant of a schoolboy, not a message meant for him. But Yochanan stopped and listened. He took the verse as an omen — a small word from Heaven dropped into a small mouth — and he changed his plans. He had intended to travel to Babylonia to visit Shmuel after Rav's death. On the strength of the child's verse, he canceled the trip.
The rabbis preserved both stories in one cluster to teach the same lesson: wisdom is the art of noticing. A stray verse from a child, a moment of meat out of sight — these are not trivia to a sage. They are signals. The world is full of small messages; it is the Jew's job to be the one listening.