Bhagwad Gita
Chapter 13, Verse 10
असक्ितरनभिष्वङ्गः पुत्रदारगृहादिषु।नित्यं च समचित्तत्वमिष्टानिष्टोपपत्तिषु।।13.10।।
Non-attachment, non-identification of the Self with son, wife, home, and the rest, and constant even-mindedness in the face of the attainment of both desirable and undesirable.