yah sarvatranabhisnehas tat tat prapya subhasubham nabhinandati na dvesti tasya prajna pratisthita
Translation
He who is without attachment, who does not rejoice when he obtains good, nor lament when he obtains evil, is firmly fixed in perfect knowledge.
Purport
Characteristics of enlightened person
Bhagvan Shri Krishna further explains the characteristics of enlightened person. Bhagvan said that a person who is without material attachment to both good and bad. Who does not rejoice when obtains something good nor lament when achieves something bad, means one who remains un effected with the physical changes is considered to be the man of perfect knowledge.
