✅ Answer: Please refer to the following verses and narrations:

قال اللَّه تعالي : وَ مَا مُحَمَّدٌ إِلَّا رَسُولٌ قَدْ خَلَتْ مِن قَبْلِهِ الرُّسُلُ أَفَإِن مَّاتَ أَوْ قُتِلَ انقَلَبْتُمْ عَلَى أَعْقَابِكُمْ...

And Muhammad (peace be upon him) is no more than a messenger; many messengers have passed before him. If he dies or is killed, will you turn back on your heels? (Surah Aal-e-Imran, Ayah 144)

📖 Surah Aal-e-Imran, Ayah 144

📚 Tafseer al-Ayashi, Vol. 1, p. 200

1⃣عَبْدالصَّمَد بْنُ بَشِیر عَنْ أَبِی عَبْداللَّه علیه السلام قَالَ: تَدْرُونَ مَاتَ النَّبِیُّ صلی الله علیه و آله أَوْ قُتِلَ إِنَّ اللَّهَ یَقُولُ أَ فَإِنْ ماتَ أَوْ قُتِلَ انْقَلَبْتُمْ عَلی أَعْقابِکُمْ فَسُمَ قَبْلَ الْمَوْتِ إِنَّهُمَا سَمَّتَاهُ فَقُلْنَا إِنَّهُمَا وَ أَبَوَیْهِمَا شَرُّ مَنْ خَلَقَ اللَّهُ

Imam Sadiq (peace be upon him) said: 'Do you know whether the Prophet (peace be upon him) died naturally or was killed? Indeed, Allah says, 'If the Prophet dies or is killed, will you turn back on your heels?' The Prophet (peace be upon him) was poisoned before his death. It was those two women who poisoned him.'

So we said and believed that these two women and their fathers are the worst of Allah’s creation!

📚 Al-Faqih, Vol. 2, p. 350

2⃣رُوِیَ عَنْ أَبِی الصَّلْتِ عَبْدِ السَّلَامِ بْنِ صَالِحٍ الْهَرَوِیِّ قَالَ سَمِعْتُ الرِّضَا یَقُولُ وَ اللَّهِ مَا مِنَّا إِلَّا مَقْتُولٌ شَهِیدٌ فَقِیلَ لَهُ فَمَنْ یَقْتُلُکَ یَا ابْنَ رَسُولِ اللَّهِ قَالَ شَرُّ خَلْقِ اللَّهِ فِی زَمَانِی یَقْتُلُنِی بِالسَّمِّ ثُمَّ یَدْفِنُنِی فِی دَارٍ مُضَیَّقَةٍ وَ بِلَادِ غُرْبَةٍ أَلَا فَمَنْ زَارَنِی فِی غُرْبَتِی کَتَبَ اللَّهُ عَزَّ وَ جَلَّ لَهُ أَجْرَ مِائَةِ أَلْفِ شَهِیدٍ و مِائَةِ أَلْفِ صِدِّیقٍ وَ مِائَةِ أَلْفِ حَاجٍّ وَ مُعْتَمِرٍ و مِائَةِ أَلْفِ مُجَاهِدٍ وَ حُشِرَ فِی زُمْرَتِنَا وَ جُعِلَ فِی الدَّرَجَاتِ الْعُلَی مِنَ الْجَنَّةِ رَفِیقَنَا

Abu Salt said: 'I heard Imam Reza (peace be upon him) say: There is no one from us except that they will either be poisoned or killed!'

It was said to him: 'O son of the Messenger of Allah, who will kill you?' He replied: 'The worst of Allah’s creation in my time will poison me, and then he will bury me in a narrow house in a foreign land. Know that anyone who visits me in a foreign land will be rewarded by Allah with the reward of one hundred thousand martyrs, one hundred thousand truthful ones, one hundred thousand pilgrims and performers of Umrah, and one hundred thousand Mujahideen. They will be gathered with us and will be companions with us in the highest levels of Paradise!'

📚 Kifayat al-Athar

3⃣جُنَادَة بْنِ أَبِی أُمَیَّةَ قَالَ قَالَ الْحَسَنُ بْنُ عَلِیٍّ صَلَوَاتُ اللَّهِ عَلَیْهِما وَاللَّهِ لَقَدْ عَهِدَ إِلَیْنَا رَسُولُ اللَّهِ صلی الله علیه و آله أَنَّ هَذَا الْأَمْرَ یَمْلِکُهُ اثْنَا عَشَرَ إِمَاماً مِنْ وُلْدِ عَلِیٍّ وَ فَاطِمَةَ مَا مِنَّا إِلَّا مَسْمُومٌ أَوْ مَقْتُولٌ

Imam Hasan al-Mujtaba (peace be upon him) said: 'By Allah, the Messenger of Allah (peace be upon him) made a pact with us that twelve Imams from the children of Ali and Fatimah (peace be upon them) would be the rulers of this matter. There is none of us except that they will either be poisoned or killed!'

📚 Al-Bihar, Vol. 44, p. 152

4⃣رُوِیَ عَنِ الصَّادِق عَنْ آبَائِهِ علیهم السلام: أَنَّ الْحَسَنَ علیه السلام قَالَ لِأَهْلِ بَیْتِهِ إِنِّی أَمُوتُ بِالسَّمِّ کَمَا مَاتَ رَسُولُ اللَّهِ صلی الله علیه وآله قَالُوا وَ مَنْ یَفْعَلُ ذَلِکَ قَالَ امْرَأَتِی جَعْدَةُ بِنْتُ الْأَشْعَثِ بْنِ قَیْسٍ فَإِنَّ مُعَاوِیَةَ یَدُسُّ إِلَیْهَا وَ یَأْمُرُهَا بِذَلِکَ قَالُوا أَخْرِجْهَا مِنْ مَنْزِلِکَ وَ بَاعِدْهَا مِنْ نَفْسِکَ قَالَ کَیْفَ أُخْرِجُهَا وَ لَمْ تَفْعَلْ بَعْدُ شَیْئاً وَ لَوْ أَخْرَجْتُهَا مَا قَتَلَنِی غَیْرُهَا وَ کَانَ لَهَا عُذْرٌ عِنْدَ النَّاس

It has been narrated from Imam Sadiq (peace be upon him) through their ancestors that Imam Hasan al-Mujtaba (peace be upon him) said to his family: 'I will die like the Messenger of Allah (peace be upon him), poisoned!' They asked: 'Who will do this?' He replied: 'My wife, Jada, the daughter of Ash'ath ibn Qays (may Allah curse her), because Muawiya secretly sends her and commands her to do so.' They said: 'Expel her from your house and distance yourself from her.' He replied: 'How can I expel her when she hasn’t done anything yet? If I expel her, no one but her will kill me, and she will have an excuse before the people!'

📚 Basa'ir al-Darajat, p. 146

4⃣عن أَبِی بَصِیر عَنْ أَبِی عَبْداللَّه علیهما السلام قَالَ: سُمَّ رَسُولُ اللَّهِ یَوْمَ خَیْبَرَ فَتَکَلَّمَ اللَّحْمُ فَقَالَ یَا رَسُولَ اللَّهِ إِنِّی مَسْمُومٌ قَالَ فَقَالَ النَّبِیُّ صلی الله علیه و آله عِنْدَ مَوْتِهِ الْیَوْمَ قَطَعَتْ مَطَایَایَ [مطای] الْأُکْلَةُ الَّتِی أَکَلْتُ بِخَیْبَرَ وَ مَا مِنْ نَبِیٍّ وَ لَا وَصِیٍّ إِلَّا شَهِیدٌ

Imam Sadiq (peace be upon him) said: 'The Messenger of Allah (peace be upon him) was poisoned on the day of Khaybar. The meat spoke and said: 'O Messenger of Allah, I am poisoned!'

The Imam said: 'When the Messenger of Allah (peace be upon him) was on his deathbed, he said: 'That food I ate in Khaybar severed my back, and there is no Prophet or successor except that they are martyrs!'

📚 Al-Kafi, Vol. 1, p. 532

6⃣بِهَذَا الْإِسْنَاد أَنَّ أَمِیرَ الْمُؤْمِنِینَ قَالَ لِأَبِی بَکْرٍ یَوْماً لا تَحْسَبَنَّ الَّذِینَ قُتِلُوا فِی سَبِیلِ اللَّهِ أَمْواتاً بَلْ أَحْیاءٌ عِنْدَ رَبِّهِمْ یُرْزَقُونَ وَ أَشْهَدُ أَنَّ مُحَمَّداً رَسُولُ اللَّهِ مَاتَ شَهِیداً

One day, Amir al-Mu'minin (peace be upon him) said to Abu Bakr: 'Never consider those who are killed in the way of Allah as dead, rather they are alive and provided for by their Lord.' And I bear witness that the Messenger of Allah (peace be upon him) died a martyr!

7⃣ Salim ibn Qays al-Hilali narrated from Abdullah ibn Abbas that in a narration, the Messenger of Allah (peace be upon him) said:

Translation: The Messenger of Allah (peace be upon him) said: 'O people! When I become a martyr, Ali (peace be upon him) is more deserving of you than yourselves....' Until he says: 'Then Ali ibn Abi Talib (peace be upon him), while crying, stood up and said: 'My father and mother be sacrificed for you, O Messenger of Allah, will you be killed?' He replied: 'Yes! I will die a martyr from poison, and you will be killed by a sword, and your beard will be dyed with your blood. My son Hasan will be poisoned, and my son Husayn will be killed with a sword, and he will be killed by a rebellious son of a rebellious, illegitimate son!'

فَقَالَ یَا أَیُّهَا النَّاسُ إِذَا أَنَا اسْتُشْهِدْتُ فَعَلِیٌّ أَوْلَی بِکُمْ مِنْ أَنْفُسِکُمْ.... فَقَامَ عَلِیُّ بْنُ أَبِی طَالِبٍ علیهما السلام وَ هُوَ یَبْکِی فَقَالَ بِأَبِی أَنْتَ وَ أُمِّی یَا رَسُولَ اللَّهِ أَ تُقْتَلُ قَالَ نَعَمْ أَهْلِکُ شَهِیداً بِالسَّمِّ وَ تُقْتَلُ أَنْتَ بِالسَّیْفِ وَ تُخْضَبُ لِحْیَتُکَ مِنْ دَمِ رَأْسِکَ وَ یُقْتَلُ ابْنِیَ الْحَسَنُ بِالسَّمِّ وَ یُقْتَلُ ابْنِیَ الْحُسَیْنُ بِالسَّیْفِ یَقْتُلُهُ طَاغٍ ابْنُ طَاغٍ دَعِیُّ بْنُ دَعِیٍّ

📚 Kitab Salim ibn Qays al-Hilali, Vol. 2, p. 838, Hadith 42

📚 Al-Bihar, Vol. 33, p. 267, B 20, Hadith 534

📚 Basa'ir al-Darajat, p. 146

Imam Sadiq (peace be upon him) said: 'A Jewish woman at Khaybar poisoned the Prophet (peace be upon him) with a lamb's shoulder. The Prophet loved the shoulder and disliked the thigh because it was closer to the place of impurity! When the food was brought to the Prophet, he ate from the shoulder, which he loved. Then, as Allah willed, he ate a portion of it, and the shoulder spoke: 'O Messenger of Allah, I am poisoned!' The Prophet abandoned it, and the poison kept returning to him until he passed away. May peace be upon him!'

8⃣عَنْ عَبْدِ اللَّهِ بْنِ مَیْمُونٍ الْقَدَّاحِ عَنْ أَبِی عَبْدِ اللَّهِ علیهما السلام قَالَ: سَمَّتِ الْیَهُودِیَّةُ النَّبِیَّ صلی الله علیه و آله فِی ذِرَاعٍ قَالَ وَ کَانَ رَسُولُ اللَّهِ صلی الله علیه و آله یُحِبُّ الذِّرَاعَ وَ الْکَتِفَ وَ یَکْرَهُ الْوَرِکَ لِقُرْبِهَا مِنَ الْمَبَالِ قَالَ لَمَّا أُوتِیَ بِالشِّوَاءِ أَکَلَ مِنَ الذِّرَاعِ وَ کَانَ یُحِبُّهَا فَأَکَلَ مَا شَاءَ اللَّهُ ثُمَّ قَالَ الذِّرَاعُ یَا رَسُولَ اللَّهِ إِنِّی مَسْمُومٌ فَتَرَکَهُ وَ مَا زَالَ یَنْتَقِضُ بِهِ سَمُّهُ حَتَّی مَاتَ صلی الله علیه و آله

✅ From the above narrations and others, it is clear without doubt that the Messenger of Allah (peace be upon him) was martyred on a Monday and died due to the effects of poison. In the available narrations, the reason for his martyrdom is explained, including the poison given to him by the Jewish woman at Khaybar, which kept returning to affect him, and the poison given to him by those two cursed women.

اللَّهُمَّ فَصَلِّ عَلَی مُحَمَّدٍ وَ آلِ مُحَمَّدٍ وَ عَجِّلْ لِوَلِیِّکَ الْفَرَجَ وَ الْعَافِیَةَ وَ النَّصْرَ