Surah Yaseen (Chapter 36 of the Quran) is known as the "Heart of the Quran," focusing on monotheism (Tawhid), the oneness of God's creative power, the reality of resurrection (Akhirah), and validating the mission of Prophet Muhammad as a divine messenger, all while offering consolation and guidance to believers facing disbelief and mockery. It emphasizes God's absolute sovereignty, provides moral lessons through stories like the inhabitants of a rejected town, and serves as a reminder of accountability and the ultimate reward in the afterlife, encouraging patience and steadfastness in faith.