BG 17.23
ॐ तत्सदिति निर्देशो ब्रह्मणस्त्रिविधः स्मृतः ।
ब्राह्मणास्तेन वेदाश्च यज्ञाश्च विहिताः पुरा ॥
ब्राह्मणास्तेन वेदाश्च यज्ञाश्च विहिताः पुरा ॥
oṁ tat sad iti nirdeśo brahmaṇas tri-vidhaḥ smṛtaḥ
brāhmaṇās tena vedāś ca yajñāś ca vihitāḥ purā
brāhmaṇās tena vedāś ca yajñāś ca vihitāḥ purā
Word-for-word meanings
oṁ tat sat iti — the words Oṁ, Tat, and Sat; smṛtaḥ — are called; tri-vidhaḥ — the threefold; nirdeśaḥ — appellation; brahmaṇaḥ — of Brahman; tena — [it is] out of these [three words]; brāhmaṇāḥ — [that] the brāhmaṇas; ca — and; vedāḥ — the Vedas; ca — and; yajñāḥ — sacrifices; vihitāḥ — were originated; purā — in former times.
Translation
The words Oṁ, Tat, and Sat are called the threefold appellation of Brahman, the Absolute Truth. It is out of these three words that the brāhmaṇas, the Vedas, and sacrifices were originated in the days of yore.