Regarding the subject of the Messiah, which you have mentioned, [and in particular concerning reports] reaching you, which have been spread in my name – the incident did not occur in the Orient, viz. in Isfahan, but rather, the true episode is as follows:
In the Land of Yemen, approximately 22 years ago, an individual arose, proclaiming that he was an emissary paving the way for the King Messiah. He told them that the Messiah would first reveal himself in the land of Yemen. A great number of people, both Jews and Arabs, rallied to him. He travelled around the mountains. Our brethren in Yemen sent me a full-scale written report, notifying me of his outlook, his policy, and habits – with his unconventional tendencies: they stated that he had even introduced unheard-of rituals, and they provided full textual details. They asserted that they had seen him perform certain wondrous acts. They put this as a question to me. I concluded, from the upshot of all this, that that poor fellow is an ignoramus, and lacks any fear of G-d; indeed he possesses not even a grain of wisdom. Furthermore, all the rumors of what he had said, as well as the alleged wonders he had shown – all these are to be treated as false and untrue. I became anxious for the Yemenite Jews. I prepared for them three to four leaflets on the topic of the Messiah, setting out the characteristics applicable to him, as well as the pertinent symptoms for the time of his appearance. I gave them a strict warning, that they were to caution that fellow, and warn him of the risk (a) of his being doomed, and (b) that the communities might perish with him. To sum up: He was subsequently arrested, a year later, and all his associates fled. The King of the Arabs, who had arrested him, challenged him: ‘Answer up for your deeds!’ - to which he replied: ‘I acted with integrity; I fulfilled the Lord’s commands’. He retorted, with the question: ‘What wonder can you show as proof?’ He replied: ‘Cut off my head, and I will immediately come to life!’ He said to him: ‘I cannot imagine a sign any more conclusive than that! – Sure, I, together with the world at large, will be convinced that ‘It was falsehood that our fathers inherited’! . On the spot they killed that poor fellow. May his death be an atonement for him and for all Israel. They then put a severe monetary taxation on the Jews almost everywhere. To this very day there remain some crazy people, who keep stating: ‘He is going to come to life and arise!’ These are the true facts. If you do hear that my written report has arrived at Fez in Morocco – it is quite probable that the very same communiqué I dispatched to Yemen was duly copied and forwarded to Fez.
Your Brother, signing once again, Moses son of Maimon the Sepharadi, Z Ts L.

Source: A.Z. Eshcolli “The Messianic Movements in Israel”, Bialik Institute.