Karma-Sannyāsa Yoga · Verse 20
न प्रहृष्येत्प्रियं प्राप्य नोद्विजेत्प्राप्य चाप्रियम् | स्थिरबुद्धिरसम्मूढो ब्रह्मविद्ब्रह्मणि स्थितः
na prahṛṣyet priyaṃ prāpya nodvijet prāpya cāpriyam | sthira-buddhir asammūḍho brahma-vid brahmaṇi sthitaḥ
One should not rejoice upon obtaining the pleasant, nor be agitated upon obtaining the unpleasant. Of stable intellect, unconfused, knowing Brahman, one is established in Brahman.
Stability before the pairs of opposites. Na prahṛṣyet — should not rejoice — before priyam — the pleasant — obtained.
Na udvijet — should not be agitated — before apriyam — the unpleasant. Sthira-buddhiḥ — of stable intellect — describes consistency. Asammūḍhaḥ — unconfused — describes clarity. Brahma-vit — knowing Brahman — produces brahmaṇi sthitaḥ — established in Brahman. Knowledge and stability are inseparable.