Bukhari

Hadith Commentary:
By "effect" is meant the color of that poison or any other change that may have occurred in the blessed palate of the Prophet (sallallahu alayhi wa sallam).
It is said that Bishr ibn al-Bara (radi Allahu anhu), a Companion, also ate a small piece of the meat from it and he died.
As long as he had not died, the Prophet (sallallahu alayhi wa sallam) forbade the Companions from killing that woman.
This was because he did not wish to take revenge from anyone for his own self.
This too is a great proof of his Prophethood.
When Bishr (radi Allahu anhu) died, then that woman was also killed in retribution (qisas) for him.
It is understood from this that if someone dies due to being poisoned, then the one who administered the poison can be killed in retribution (qisas), and the Hanafis have differed in this matter.
In another hadith, it is mentioned that the Prophet (sallallahu alayhi wa sallam), near his passing, said: "O Aisha! The food which I ate at Khaybar"—meaning this very poisoned meat—"has now shown its effect and has cut my jugular vein."
In this way, Allah Ta'ala granted him martyrdom (shahadah) as well (Wahidi).
This incident also refutes those extremist innovators who claim that the Prophet (sallallahu alayhi wa sallam) is absolutely 'Alim al-Ghayb' (Knower of the Unseen).
Whereas in the Noble Qur'an, Allah has clearly made him announce:
﴿وَلَوْ كُنْتُ أَعْلَمُ الْغَيْبَ لَاسْتَكْثَرْتُ مِنَ الْخَيْرِ وَمَا مَسَّنِيَ السُّوءُ﴾ () (al-A'raf: 188)
That is, "If I had knowledge of the unseen, I would have accumulated much good for myself and no harm would have touched me."
Thus, those who hold the above belief are completely caught in misguidance.
May Allah grant them sound understanding.
Amin.

Hadith Commentary:
(1)
The intention of this Jewish woman was that if you are a true Messenger, then the poison will not affect you, and if you are not a true Prophet, then you will perish from this poison.
(2)
From this, it is understood that the gifts of disbelievers and polytheists can be accepted, provided that there is no harm in it and that self-interest does not play a role in accepting it.
(3)
It should be noted that eating the poisoned meat had a visible effect on your throat, which became apparent as soon as you opened your mouth, as narrated by Anas radi Allahu anhu.
(4)
From this, it is also understood that you were not ‘Alim al-Ghayb’ (Knower of the Unseen), otherwise you would have rejected that gift beforehand.
It should be remembered that due to this poison, one of your Companions, Bishr ibn al-Bara’ al-Ansari radi Allahu anhu, was martyred.

Hadith Commentary: Benefits and Issues: The Jewish chief Salam bin Mishkam’s wife, and Marhab the warrior’s sister, Zaynab bint al-Harith, out of nationalistic zeal, presented the Prophet (sallallahu alayhi wa sallam) with a poisoned goat, and she put a large amount of poison in the foreleg, which he used to prefer, so that she could eliminate him. However, nothing can have any effect without the will and permission of Allah, so her objective was not fulfilled, and the Prophet (sallallahu alayhi wa sallam) lived for three years after this incident. But since Allah, the Exalted, intended to grant him the reward of martyrdom, its effect became apparent in his final days, and he passed away. When the Prophet (sallallahu alayhi wa sallam) began to eat the meat from the foreleg, he could not chew it and he spat it out, and the bone informed him that it had been poisoned. He stopped his companions from eating, but Bishr bin al-Bara’ bin Ma’rur (radi Allahu anhu) had already swallowed a morsel and passed away. The Prophet (sallallahu alayhi wa sallam), on his own accord, let the woman go and had cupping performed between his shoulders to extract the effect of the poison. However, later, when Bishr (radi Allahu anhu) passed away, according to some weak narrations, she was killed in retribution (qisas).