Bhagavad Gita · 17.26

सद्भावे साधुभावे च सदित्येतत्प्रयुज्यते।प्रशस्ते कर्मणि तथा सच्छब्दः पार्थ युज्यते॥

sad-bhāve sādhu-bhāve cha sad ity etat prayujyate praśhaste karmaṇi tathā sach-chhabdaḥ pārtha yujyate

The word 'Sat' is used in the sense of reality and goodness. Likewise, O Partha, the word 'Sat' is used for auspicious action.

— Bhagavad Gita 17.26

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)