It is narrated from Hazrat Zaid bin Arqam (may Allah be pleased with him). He says that a Jewish man cast a spell on the Noble Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) suffered from this for a few days, but then Hazrat Jibreel came to him and said, "Such-and-such a Jew has cast a spell on you and has tied some knots for you." So the Prophet (peace and blessings be upon him) sent Hazrat Ali (may Allah be pleased with him) towards those knots (the thread with knots), and Hazrat Ali (may Allah be pleased with him) brought it and presented it to the Prophet (peace and blessings be upon him). Whenever the Prophet (peace and blessings be upon him) untied a knot from those knots, he would feel lighter. The narrator says: Thus, the Prophet (peace and blessings be upon him) stood up as if he had been released from a restraint. But the Prophet (peace and blessings be upon him) never mentioned this matter to that Jewish man, nor did that Jew ever recognize anything from the face of the Prophet (peace and blessings be upon him).