Sayyiduna Zayd bin Arqam (may Allah be pleased with him) narrates that a Jew used to come to the Prophet Muhammad (peace and blessings be upon him), and the Prophet (peace be upon him) used to trust him. He (the Jew) tied knots (to perform magic on the Prophet, peace be upon him) and placed this act in the well of an Ansari. Because of this, the Prophet (peace be upon him) remained ill for a few days (according to the narration of Sayyidah Aisha, may Allah be pleased with her, for six months). Two angels came to visit the Prophet (peace be upon him) during his illness; one sat near his head and the other at his feet. One asked the other: "Do you know what is ailing him?" The other replied: "So-and-so (the Jew) who used to come to him, tied knots and placed his act in the well of such-and-such Ansari. If someone is sent to bring those knots, he will find the water of the well yellow." Jibreel (peace be upon him) came to the Prophet (peace be upon him) with the Mu'awwidhatayn (Surah Al-Falaq and Surah An-Naas) and said: "So-and-so Jew has performed magic on you, and the act of magic is in such-and-such well." The Prophet (peace be upon him) sent a man (according to one narration, Sayyiduna Ali, may Allah be pleased with him), who saw that the water had turned yellow, and he brought back the knots. Jibreel (peace be upon him) told the Prophet (peace be upon him) to recite one verse and untie one knot at a time. The Prophet (peace be upon him) untied one knot, then kept reciting a verse and untying the knots. As soon as a knot was untied, the Prophet (peace be upon him) would feel relief, until he was completely cured. In one narration, it is mentioned that the Prophet (peace be upon him) stood up as if he had been tied with ropes and was set free by untying the ropes. That (Jewish magician) used to come to the Prophet (peace be upon him) after this incident, but the Prophet (peace be upon him) never mentioned anything to him nor ever scolded him, until he died.