how did the prophet died?

ak_m_f wrote: how did the Prophet died? I read that; At khaibar, the Jews cooked a sheep containing poison presented it the Prophet. and he died because of it is it true?

Allah has forbidden Messengers to be killed by human hands.  One of the differences btw prophets and messengers is that prophets could be killed by individuals but messengers could not be killed by any other hand than the Hand of Allah. 

All messengers are prophets but not all prophets are messengers.  Examples of prophets who are messengers are: Muhammad (SAW), Jesus, Moses, David.  A messenger comes with a devine revilatin as in the Quran, Gospel, Tora, Psalms of David.  the rest of the prophets hadn't come with a revilation so they are not 'messengers'. Their role is to confirm and persist in applying the message with their generation of people.   examples of prophets are: Adam, Noah, Abraham, Ismail, Issac, Sulaiman, and more than 200 others.  

So to answer your question, Sayyidina Muhammad (SAW) did not die because he was poisoned.  He died from a severe fever that came after he had completed his message and Allah had confirmed that the religion of Allah is Islam.  

ak_m_f wrote: I read that; At khaibar, the Jews cooked a sheep containing poison presented it the Prophet. and he died because of it is it true?

I don't think this is true. Prophet Mohammad died after completing his assigned task, as natural death. For complete details read any good book on sirah tun Nabi. Here is one such good book, free online. http://www.witness-pioneer.org/vil/Books/MH_LM/prophets_sick ness_and_death.htm