Manusmriti

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एकाक्षरं परं ब्रह्म प्राणायामः परं तपः । सावित्र्यास्तु परं नास्ति मौनात् सत्यं विशिष्यते ॥ ८३ ॥

sanskrit

The monosyllable (Om) is the highest Brahman, (three) suppressions of the breath are the best (form of) austerity, but nothing surpasses the Savitri truthfulness is better than silence.

english translation

ekAkSaraM paraM brahma prANAyAmaH paraM tapaH | sAvitryAstu paraM nAsti maunAt satyaM viziSyate || 83 ||

hk transliteration by Sanscript