Literature Reference: 吟咏心自愉。—— 《读书》 Singing brings joy to the heart. Source from 'Du Shu' by Liu Zongyuan.
自: Nature; the true self.
愉: Harmony and joy, a life of refined elegance and honor. With exceptional talents and a prosperous official career, though modest in wealth, one enjoys a lifetime of bliss and contentment.
Meaning: Self-delight signifies inner contentment and joy.