Manusmriti

siva.sh/manusmriti/2/81

ओङ्कारपूर्विकास्तिस्रो महाव्याहृतयोऽव्ययाः । त्रिपदा चैव सावित्री विज्ञेयं ब्रह्मणो मुखम् ॥ ८१ ॥

sanskrit

Know that the three imperishable Mahavyahritis, preceded by the syllable Om, and (followed) by the three-footed Savitri are the portal of the Veda and the gate leading (to union with) Brahman.

english translation

oGkArapUrvikAstisro mahAvyAhRtayo'vyayAH | tripadA caiva sAvitrI vijJeyaM brahmaNo mukham || 81 ||

hk transliteration by Sanscript