Yā Sīn is the 36th 'chapter' of the Qur'an with 83 ayat, and is one of the Meccan suras. It is often referred to as "the Heart of the Qur'an" in accordance with a well-known hadith of the Islamic prophet, Muhammad. The sura focuses on establishing the Qur'an as a divine source, and it warns of the fate of those that mock God's revelations and are stubborn.