The Quran, the holy book of Islam, is written in classical Arabic, which is also known as Quranic Arabic. Classical Arabic is a formal language that has its own grammar and syntax rules. The Quran was revealed to the Prophet Muhammad in Arabic, and it is believed to be the uncorrupted word of God as dictated to the Prophet Muhammad by the angel Gabriel. The Arabic language was the primary language of the Arabian Peninsula at the time of the revelation of the Quran in the seventh century. The Quran is considered the ultimate source of knowledge and teachings for Muslims all over the world. Therefore, the original language of the Quran is Arabic.