Regarding your question about the Arabian Peninsula and how jizyah was taken from the Christians of Najran—meaning they resided there—and similarly the Jews in Khaybar by allowing them to stay in exchange for half of the harvest as mentioned in the hadiths, despite it not being permissible for two religions to coexist in the Peninsula; and your suggestion that this appears to be a contradiction, here is the answer:
Different opinions have been reported by the jurists regarding the boundaries of the Arabian Peninsula in which two religions cannot coexist, but rather only Islam.
By examining these opinions, it becomes clear that the length of the Arabian Peninsula extends from Aden Abyan to the rural areas of Iraq, and its width extends from al-Ubulla (near Basra), i.e., the rural areas of Iraq, to Jeddah on the sea. This means that Yemen and Khaybar are both part of the Arabian Peninsula.
This is based on the following:
a. It is stated in the book The Funds in the Khilafah State (Al-Amwal): "As for the Arabian Peninsula, including Yemen..." (p. 50).
b. Ibn al-Arabi quoted al-Haytham ibn Adi stating: "The Peninsula is from al-Udhayb to Hadramaut." Al-Udhayb is in the land of Iraq, four miles past al-Qadisiyyah on the borders of the desert, as mentioned in Mu'jam al-Buldan.
c. Al-Asma'i stated: "The Arabian Peninsula is what is between Aden Abyan to the rural areas of Iraq in length, and its width is from al-Ubulla to Jeddah." Al-Ubulla is in the region of Basra. What was narrated by Ibn al-Arabi and al-Asma'i is well-known among many jurists.
d. Abu Dawud narrated from Sa’id ibn Abd al-Aziz who said: "The Arabian Peninsula is what is between the valley to the furthest part of Yemen, to the borders of Iraq, to the sea."
e. It was narrated from Abu Ubaydah ibn al-Jarrah that the Prophet (saw) said:
"Expel the Jews of the people of Hijaz and the people of Najran from the Arabian Peninsula." (Reported by Ahmad). Al-Haythami stated that Ahmad narrated it with several chains, the men of two of them are trustworthy (thiqat) and their chains are connected (muttasil). In the narration of al-Darimi via Abu Ubaydah ibn al-Jarrah, he said: Among the last things the Messenger of Allah (saw) spoke was:
"Expel the Jews from the Hijaz and the people of Najran from the Arabian Peninsula." Thus, Umar (ra) expelled them.
f. It is stated in al-Qamus al-Muhit under the entry (j-z-r): "The Arabian Peninsula: what is surrounded by the Indian Sea and the Levantine Sea, then the Tigris and Euphrates; or what is between Aden Abyan to the edges of Ash-Sham in length, and from Jeddah to the edges of the rural areas of Iraq in width."
Therefore, what we consider most correct is that the Arabian Peninsula is:
(From Aden Abyan to the edges of Ash-Sham in length, and from Jeddah on the sea to the edges of the rural areas of Iraq in width). This means Najran and Khaybar are part of it. We have affirmed this in Al-Amwal, where we stated: "The Arabian Peninsula including Yemen."
As for the fact that the Messenger of Allah (saw) took jizyah from the Christians of Najran and dealt with the Jews of Khaybar on the basis of half the fruit (sharecropping) and allowed them to stay there, this is correct. However, this was prior to his (saw) hadiths regarding the expulsion of Jews and Christians from the Arabian Peninsula. This is clear from the following:
a. The hadith of Aisha (ra):
"The last testament of the Messenger of Allah (saw) was: Two religions shall not be left in the Arabian Peninsula." (Reported by Ahmad). Al-Haythami said its narrators are the narrators of as-Sahih.
b. In the previously mentioned narration of al-Darimi via Abu Ubaydah (ra): "Among the last things the Messenger of Allah (saw) spoke was: 'Expel the Jews from the Hijaz and the people of Najran from the Arabian Peninsula.' Thus, Umar (ra) expelled them."
c. Al-Bukhari reported via Sufyan ibn Uyaynah from Sulayman ibn Abi Muslim al-Ahwal, who heard Sa’id ibn Jubayr hearing Ibn Abbas (ra) saying: "Thursday, and what a Thursday it was!" Then he wept until his tears wetted the pebbles. I said: "O Abu Abbas, what is 'Thursday'?" He said: "The pain of the Messenger of Allah (saw) became severe..." until he said: The Messenger of Allah (saw) said:
"Expel the polytheists from the Arabian Peninsula..." the hadith. This means the Messenger (saw) said this during his final illness.
Therefore, there is no contradiction between taking jizyah from the Christians of Najran and dealing with the Jews of Khaybar through musaqat (sharecropping) for half the fruit and allowing them to stay. There is no contradiction between this and the command of the Messenger of Allah (saw) to expel the Jews and Christians from the Arabian Peninsula, as this command was in his final days (saw), and it thus abrogates (nasikh) what preceded it.
2 Dhul-Hijjah 1425 AH 12/01/2005 CE