As you have read, the Qur'an claims that it is pure Arabic. But this is not true. First the erroneous claim: Qur'an 46:2 "And before it the Book of Musa was a guide: and this is a Book verifying (it) in the Arabic language." Qur'an 39:27 "We have coined for man in this Qur'an every kind of parable in order that they may receive admonition. (It is) a Qur'an in Arabic, without any crookedness (therein)." Qur'an 41:3 "A Scripture Book, whereof the verses are explained in detail; a Qur'an in Arabic, for people who have knowledge." Then... Qur'an 41:44 "Had We sent this as a Qur'an (in the language) other than Arabic, they would have said: 'Why are not its verses explained in detail? What! (a foreign tongue, a Book) not in Arabic and (a Messenger) an Arab?' Say (to them, Muhammad): 'It is a Guide to those who believe; and for those who do not believe it, there is a deafness in their ears, and a blindness in their (eyes)!'" While the purpose of these Qur'an quotes was to confirm Allah's Arabic claims, consider the number of words the translators had to add inside the parenthesis for Allah's message to make any sense.
The Qur'an's Arabic assertion is not true. There are many foreign words or phrases which are employed in the Qur'an. Arthur Jeffrey, in his book Foreign Vocabulary of the Qur'an devoted 300 pages to this study. One must wonder why so many foreign words were borrowed, as they refute the Arabic claim and put doubt on whether "Allah's language" was sufficient to explain what Muhammad intended. According to Alphonse Mingana in his Syriac Influence on the Style of the Qur'an, almost all of the religious terms found in Allah's book were derived from Christian Syriac. These include the words Muhammad used for: priest, Christ, judgment, scribes, parable, salvation, infidel, sacrifice, resurrection, heaven, garden, angel, holy spirit, soul, sign, verse, proof, God, prayer, fast, sin, pagan, hanif, Muslim, idolatry, Qur'an, faith, creation, grace, and even the zakat tax. The proper names of Biblical personages found in the Qur'an are used in their Syriac form rather than Hebrew or Arabic. These include: Solomon, Pharaoh, Isaac, Ishmael, Israel, Jacob, Noah, Zachariah, Mary, John, Jonah, and Isa for Yahshua. The words for demons, the path, disciple, and Muhammad's first "god," Ar-Rahman are Persian. Rahman is a derivative of the Persian name for the Devil.
Adam and Eden are Akkadian words from Mesopotamia. A more correct term for "Adam" in Arabic would be basharan or insan, meaning "mankind." "Eden" should have been janna in Arabic, which means "garden." Yet the foreign words were repeated over twenty times. Abraham, sometimes recorded as Ibrahim, comes from the Assyrian language. The correct Arabic equivalent is Abu Raheem.
Harut and Marut are Persian names for angels. The Persian "sirat" meaning "the path" was repeated thirty times yet it has an Arabic equivalent, altareeq, which was not used. The Persian "hoor" meaning "disciple" has the Arabic equivalent, tilmeeth. Guess which one Allah selected?
The Persian word "Jinn" meaning "demon" is used consistently throughout the Qur'an. Entire surahs are dedicated to Satan's allies. Yet there is an Arabic equivalent, Ruh. Going the other way, Islam's decadent heaven is called by the Persian word "firdaus" meaning "the highest or seventh heaven" rather than the Arabic equivalent, jannah.
Some of the Hebrew words are: heber, Sakinah for Yahweh's presence, maoon, taurat, jehannim, and tufan, which means deluge. The Greek word "Injil," which means "gospel" was borrowed, even though there is an Arabic equivalent, bisharah. Iblis, the Qur'anic name for Lucifer or Satan, is not Arabic. It is a corruption of the Greek word Diabolos. Muhammad said that believing in the "Day of Resurrection" was a third of his message, yet he chose a Christian Syriac derivative of an Aramaic word, Qiyama, for resurrection rather than the Arabic one.
The Qur'an is fixated on stripping the Messiah of his divinity and of the sacrifice he made to save mankind. You'd think that Allah would at least get his name right. But Christ's Qur'anic name, "Isa," is erroneously applied. Isa is the Arabic equivalent of Esau, the name for the twin brother of Jacob. The correct Arabic name for Yahshua would be Yesuwa, yet the "all-knowing" Allah doesn't mention it. And this mistake is unlike the erroneous translations of the Bible. God got his name right in Hebrew; the English translators erred. Even Arabic speaking Christians in the Middle East use the name Yesuwa for "Jesus." Only Muslims use Isa.
By way of recap, we've learned that the Qur'an wasn't, as Allah claims, a book memorialized on heavenly tablets, but instead consisted of evolving text. The oldest Qur'ans differ from one another and from today's version. We discovered that the original written copies were devoid of diacritical points, so most words were chosen on the basis of educated guesses. Their meanings were interpreted two centuries after the Qur'an was revealed orally. It's not pure Arabic as Allah claims, as there are a plethora of foreign words. There are also missing words, wrong words, and meaningless words. And most important of all, the leading authority of the initial script of the Qur'an, studying the oldest fragments says: "One out of every five verses is indecipherable - meaningless in any language."