It is narrated from Hazrat Zaid bin Arqam (may Allah be pleased with him) that once a Jew cast a spell on the Holy Prophet (peace and blessings be upon him), due to which the Holy Prophet (peace and blessings be upon him) remained ill for several days. Then Hazrat Jibreel came and said that a Jewish man has cast a spell on you; he has tied some knots on something and placed it in such-and-such well. You should send someone to bring it from there. The Holy Prophet (peace and blessings be upon him) sent Hazrat Ali (may Allah be pleased with him), who took out that thing. Hazrat Ali (may Allah be pleased with him) brought it, and the Holy Prophet (peace and blessings be upon him) opened it. As each knot was untied, the Holy Prophet (peace and blessings be upon him) became healthier, as if he had been released from a rope. However, the Holy Prophet (peace and blessings be upon him) neither mentioned that Jew nor saw his face until his passing.