Chapter 02 – śloka 38:

सुखदुःखे समे कृत्वा लाभालाभौ जयाजयौ ।
ततो युद्धाय युज्यस्व नैवं पापमवाप्स्यसि ॥

sukhaduḥkhe same kṛtvā lābhālābhau jayājayau ।
tato yuddhāya yujyasva naivaṁ pāpamavāpsyasi ॥

      Chapter 02 – śloka 38

sukhaduḥkhe – pleasure and pain
same – as equal
kṛtvā – having treated
lābhālābhau – gain and loss
jayājayau – success and defeat

tataḥ – then
yuddhāya – for battle
yujyasva – engage
na – no
eva – in this way
pāpam – sin
avāpsyasi – you will incur


Meaning (in full)

Treating pleasure and pain, gain and loss, success and defeat as equal, engage in the battle [for the sake of duty]. This way, you will not incur sin.


Context

Man experiences hope and despair, pleasure and pain, loss and gain, and victory and defeat all through his life. The noble one rises above these opposites, practicing even-mindedness and detachment as he goes about his duty, without being attached to the fruits of his actions.


Chapter 02 – śloka 39:

एषा तेऽभिहिता साङ्ख्ये बुद्धिर्योगे त्विमां श‍ृणु ।
बुद्ध्या युक्तो यया पार्थ कर्मबन्धं प्रहास्यसि ॥

eṣā te’bhihitā sāṅkhye buddhiryoge tvimāṁ ś‍ṛṇu ।
buddhyā yukto yayā pārtha karmabandhaṁ prahāsyasi ॥

      Chapter 02 – śloka 39

Word-by-word meaning

eṣā – all this or so far;
te – to you;
abhihitā – explained;
sāṅkhye – in regard to the nature of the Self;
buddhiḥ – wisdom;
yoge – in regard to yoga;
tu – indeed;
imām – this;
śṛṇu – listen;
buddhyā – by wisdom;
yuktaḥ – endowed;
yayā – by which;
pārtha – Arjuna,
the son of Prtha;
karmabandham – bondage of action-reaction;
prahāsyasi – you shall be released from;


Meaning (in full)

So far, the knowledge of sāṅkhya (the nature of the Self) has been explained to you. Now listen, O Arjuna, to the wisdom of yoga (the means of attaining the knowledge explained earlier). Endowed with this, you shall be released from the bondage of karma (action and reaction).


Context

Having thus explained the knowledge of the immortal soul or the Self (sāṅkhya), Krishna now teaches Arjuna its practical wisdom, buddhi yoga. Using this, the discriminating intellect can bring about detachment from the bondage to one’s actions and results.