The following excerpt is taken from “The Lawful and Prohibited in Islam” by Yusuf Al-Qaradawi pg. 56-57 and pg. 59-60 respectively:
Animals Slaughtered by The People of the Book
We have seen that Islam emphasizes that the animal must be slaughtered in a prescribed manner. The polytheists of Arabia and other nations had made animal sacrifice an act of worship, or rather an integral part of their belief system and a pillar of their religion, seeking to propitiate their deities by sacrificing animals either at their special altars or by mentioning their names over them. Islam abolished these pagan rites and ordained that no name except that of Allah be mentioned while slaughtering, and it prohibited what was sacrificed at an altar or dedicated to anyone other than Allah Subhanahu wa Ta’ala.
Now although the People of the Book—the Jews and Christians —are essentially believers in one God, some Muslims nevertheless supposed that in matters related to food the People of the Book were to be treated in the same manner as idolaters. Thereupon Allah Ta’ala granted special permission to Muslims in the matter of eating with the People of the Book and in the matter of marriage to their women. In Surah al-Maidah, the last surah of the Qur’an to be revealed, Allah says, Today whatever is good is made lawful to you. And the food of those who were given the Scripture (before you) is permitted to you and your food is permitted to them…. (5:6 (5))
The meaning of these verses is, in brief, that from this day forward all good, pure, and wholesome things are permitted to you Muslims; consequently, there can be no more bahirah, saibah, wasilah, or ham. Since Allah did not prohibit it, the food of the Jews and the Christians is permitted to you on the basis of the original permissibility of things, and likewise you can share your food with them. Accordingly, you can eat the flesh of the animals they have slaughtered or hunted, and they can eat what you have slaughtered or hunted.
While Islam takes an uncompromising attitude toward polytheists, it is lenient toward the People of the Book, for they are closer to Muslims in their belief in divine revelation, prophethood, and other fundamentals of . Islam permits us to eat with them, to marry their women, and, in general, to have social relations with them. It may be that, by interacting with Muslims in an Islamic environment and observithe beliefs, practices, and characters of Muslims, they may come to realize that Islam is in truth their own religion but with a higher level of spirituality, a more perfect Shari’ah, and books of greater authenticity, (That is, the Holy Qur’an, the books of Ahadith, and the Sirah (biography) of the Prophet. (Trans.)) while also free of the influence of paganism, man-made concepts, and falsehood.
The application of the phrase, “the food of those who were given the Scripture,” is general and includes their meats, produce, and other foods. All of these are halal for us excepting what is haram in itself, e.g., the flesh of a dead animal, pork, and flowing blood, as these are haram regardless of whether they are obtained from a Christian, a Jew or a Muslim
The Meat of Zoroastrians and Others Like Them
A difference of opinion exists among jurists concerning the meat of animals slaughtered by the Zoroastrians or Parsees (Majus). The majority forbids the eating of it because they are polytheists, while others say that it is halal because the Prophet (peace be on him) said, “Treat them as you treat the People of the Book.” (Reported by Malik and al-Shafi’i. What comes at the end of this hadith, “Do not marry their women nor eat their meat,” is not considered authentic by the compilers of Ahadith.)
The Prophet (peace be on him) accepted jizyah from the Zoroastrians of Hajar. (Reported by al-Bukhari and others.) In the chapter on slaughtering in Ibn Hazm’s book, Al-Muhalla, (Vol. 7, p. 456.)the author says, “They are also a People of the Book; hence all the rules related to the People of the Book apply to them.” (Ibn Hazm’s opinion undoubtedly carries great weight. He was very meticulous in applying the texts of the Qur’an and Ahadith, as well as being knowledgeable concerning the history of nations and their customs. Al-Baghdadi, in his book Al-Farq Bayn al-Firaq, states: “The Magians (Zoroastrians) claim that Zoraster was a prophet” Some modern Islamic scholars who have conducted researches into ancient cultures, such as Abul Kalam Azad, support this view.) Likewise the Sabeans are classified by Abu Hanifah as belonging to the category of People of the Book. (Some researchers of our time have attempted to extend the circle of People of the Book to include idolatrous such as Hindus and Buddhists, but they are stretching the matter too far. See, for example, Tafsir al-Manar, vol. 6, in the interpretation of the ayah, “The food of those who were given the Scripture is permitted to you,” in the chapter dealing with the food of idolatrous and marriage to their women.)
A Rule: What We Do Not See Should Not Be Probed Into
It is not required of the Muslim to inquire about what he has not witnessed, i.e., How was the animal killed? Did the manner of slaughter meet the Islamic conditions? Was the name of Allah mentioned while slaughtering or not? If the animal was slaughtered by a Muslim, even if he is ignorant or sinful, or by someone from among the People of the Book, eating it is halal for us.
We have already narrated a hadith in which it wasaid to the Prophet (peace be on him): “People bring us meat and we do not know whether they have mentioned the name of Allah over it or not. Shall we eat it or not?” and the Prophet (peace be on him) replied, “Mentionthe name of Allah (over it) and eat.”
Concerning the application of this hadith, scholars say: This is proof that the actions and practices of people are ordinarily considered to be correct and appropriate, while deviation or error must be proved.
Al-Qaradawi, Yusuf (1960). The Lawful and Prohibited in Islam. (p. 56-57, pg. 59-60). http://www.islamicweblibrary.com/wp-content/uploads/2019/06/TheLawfulAndTheProhibitedInIslamal-halalWalHaramFilIslamByShaykhYusufAlQardawi.pdf