Mohammad died in 632 AD after being poisoned by a Jewish woman as a revenge for the innocent killing of her family.
Sahih Bukhari V5, B59, N713 reported:
…Narrated 'Aisha: "The prophet in his ailment in which he died, used to say, 'O 'Aisha! I still feel the pain caused by the food I ate at 'Khaibar, and now, I feel as if my aorta is being cut from that poison." (After a failed attempt to go to Mecca Mohammad and his followers attacked and plundered the weaker Jewish settlement of Khaibar where he was poisoned)
Answer-2
Hazrat Muhammad fell ill at the age of 63. It was much later when he was poisoned by a Jewish woman. Anyhow, he also felt the effect of that poison. During his illness he passed away. That was not the cause of the attack on the Jews of Khaibar. The Jews had betrayed the Muslims and broken the pact done with the Muslims during the battle of Khandaq (Battle of Tribes). The Muslims were commanded by Almighty Allah to attack the Jews of Khaiber who always remained busy in hatching conspiracies against the Muslims. After their defeat, they asked one of the Companions to pass judgment on them. They met their end as a result of the judgment passed by their own appointed judge.
Answer 1
natural death, age factor.
Answer 2
A political enemy tricked Muhammad into eating poison in July 628. His dining companion died of it. Muhammad spat out the poison but he complained of pain from it for the rest of his life. When he died in June 632, he blamed the poison.
It may be so. But it would be an interesting poison that, in such a small quantity, took four years to activate, yet was successful in the end.
Therefore the first answer (he suffered a fever and was 61 years old) may well be the correct one.
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