jneyah sa nityasannyaasee yo na dveshti na kaanshati |
nirdvandvo hi mahaabaaho sukham bandhaatpramuchyate || 3 ||

He who does not hate anything, nor expects anything, know him to be an eternal renouncer. For one who is free from duality, O mighty-armed, he happily casts off bondage.

jneyah : know
saha : that
nitya : eternal
sannyaasee : renouncer
yaha : he who
na : does not
dveshti : hate anything
na : does not
kaanshati : expect anything
nirdvandvaha : free from duality
hi : for
mahaabaaho : O mighty-armed
sukham : happily
bandhaat : bondage
pramuchyate : casts off

During the time of the Mahabhaarata war, and even now, there existed a fixed ideal of what it means to become a renouncer, which was that one runs away from the world to some remote place. Shri Krishna needed to change that ideal completely. So he defines what it means to be a renouncer or sannyaasi in this shloka. A renouncer is one who completely gives up his ego, not external objects and situations.

In that regard, Shri Krishna says that if we have three qualities: freedom from hatred, expectation and duality, that person is a true renouncer. Firstly, if something is obstacle to happiness, or someone is giving us sorrow, we generate hatred for that person or object. Secondly, if we always keep thinking that we will become happy in the future, we generate expectations, taking consciousness away from the present and into the future. Finally, if we only get attracted to certain aspects of our existence, the other aspects will torture us and bind us. This is what is meant by duality.

So therefore, one who has become free from these 3 qualities has truly renounced the material world, even if he continues to perform his duties. This is a high standard indeed. Having clarified the definition of snanyaasi, Shri Krishna compares a sannyaasi to a karmayogi in the next shloka.