Verse
यं हि न व्यथयन्त्येते पुरुषं पुरुष्ऽअर्षभ ।समदुःखसुखं धीरं सोऽमृतत्वाय कल्पते ॥
The man whom these do not trouble nor pain, O lionhearted among men, the firm and wise who is equal in pleasure and suffering, makes himself apt for immortality.
Gītā 2·15