There must be something dual: black-white, darkness-light, sukha, happiness, distress, father-son. There must be. This is called relative world. One thing, if you understand one thing, you must know the other thing, opposite. Otherwise, it has no meaning. In the absolute world there is no such thing, opposite elements. So here, Kṛṣṇa is suggesting about the absolute duty, lābhālābhau. When there is loss or gain, you are the same. Generally, when there is gain, we are very jubilant, and when there is loss, we become morose. But here, Kṛṣṇa is teaching that, "You remain in one position, either it is loss or gain, either it is victory or defeat, either it is happiness or distress." This is brahma-bhūta.
Brahma-bhūtaḥ prasannātmā na śocati na kāṅkṣati (BG 18.54). A devotee is always prasannātmā, because his happiness is to serve Kṛṣṇa. His only business is to see Kṛṣṇa happy, that's all. This is devotion. There may be loss or gain, there may be victory or defeat, there may be distress or happiness, it doesn't matter. He's not affected with this duality. That is being taught now. Real Bhagavad-gītā begins here. Kṛṣṇa is teaching. In the last also . . . this will go on in different languages up to the end of the Bhagavad-gītā. Mām ekaṁ śaraṇaṁ vraja (BG 18.66). That's all. Saṁsiddhir hari-toṣaṇam (SB 1.2.13). Bhāgavata also confirms this. You do not look after whether it is loss or gain, but you have to see whether Kṛṣṇa is satisfied. That's all. That is your only business. That is your only business.
That is explained in the Śrīmad-Bhāgavatam:
- ataḥ pumbhir dvija-śreṣṭhā
- varṇāśrama-vibhāgaśaḥ
- svanuṣṭhitasya dharmasya
- saṁsiddhir hari-toṣaṇam
- (SB 1.2.13)
Hari-toṣaṇam. The real perfection of life is whether, by your action, Kṛṣṇa is satisfied. That is perfection. You don't consider of your personal victory, defeat, loss or gain, or distress or happiness. Therefore Bhaktivinoda Ṭhākura has sung that "When I work very difficult task for Kṛṣṇa, that difficult task becomes very happiness for me. That difficult task becomes very happiness for me." That is the standard of happiness. In the material world, there is duality. In the absolute world, there is simply happiness. There is nothing else. Just like when Kṛṣṇa is going to Mathurā, all the gopīs become very, very distressed, crying. But we cannot understand what is the happiness of that distress. That we cannot understand from this material point of view. That is greatest happiness.