Are all Qur'an words in Arabic or there are some Persian words?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions. The preponderant opinion held by the Muslim scholars is that the Qur'an is an Arabic-revealed Book in its entirety, based on Allah's Saying: {Verily, We have sent it down as an Arabic Qur'ân in order that you may understand.}[12:2]. He also Says: {And if We had sent this as a Qur'ân in a foreign language other than Arabic…}[41:44]. These two verses, among others, denote that the Qur'an contains nothing but Arabic. Imam Ash-Shafi'ee as well as the vast majority of scholars also hold this opinion. As concerns the issue of mentioning some proper names in the Qur'an such as Ibraheem (Abraham), it is not a point of discrepancy among the scholars, for the Qur'an mentioned such names as they are as a matter of precise quote. Regarding the words the Qur'an contains which conform to some non-Arabic ones, the most eligible assumption about them is that they were non-Arabic in origin then Arabs began to use them after they came into contact with the non-Arabic communities. Such words were introduced to the Arabic language and became part of it. Hence, when the Qur'an was revealed, it came to include some of these words, such as: At-Toor (Mountain in Sinai), Istabraq, Sundus (kinds of silk), etc. Allah knows best.