Mandukya UpanishadMandukya Upanishad 1
ओमित्येतदक्षरमिदं सर्वम्
Om ity etad akṣaram idaṃ sarvam
Aum (Om) — this one syllable is all this; the whole universe is this sound.
— Ekam (simplified)
📖 Story
Sajjan ran an inn where he secretly robbed and killed his guests. One evening Guru Nanak sang the Divine Name, and the song pierced Sajjan's heart. He fell weeping at the Guru's feet and turned his whole life toward goodness.