The Talmud says a dying man left everything to his one true son out of ten, and a rabbi found him by telling the sons to beat their father's grave

Tractate Bava Batra 58a tells two inheritance cases brought to Rabbi Bana'ah. In the first, a dying man said: a barrel of earth to one son, a barrel of bones to another, a barrel of wool to the third. Bana'ah asked whether the father had left land, livestock and quilts. He had, so Bana'ah divided them that way. In the second, a man overheard his wife tell their daughter that of her ten sons only one was her husband's. When he was dying he said: all my property to one son. He did not say which. The sons came to Bana'ah. He told them to go and strike their father's grave until he rose and told them which son was the heir. Nine went. One refused. Bana'ah gave him the whole estate. The other nine denounced Bana'ah to the authorities as a judge who took property from people without witnesses or evidence, and he was imprisoned. The Talmud says he was released after solving a riddle and was made a judge. The Jewish Encyclopedia calls the story a legend. Bana'ah was a Palestinian scholar of the early 3rd century who headed an academy in Tiberias, where his student Johanan later taught.