Having made — pleasure and pain, gain and loss, victory and defeat — the same, engage in battle for the sake of battle; thus you shall not incur sin.

sukha = happiness; duḥkhe = and distress; same = in equanimity; kṛtvā = doing so; lābhālābhau = both profit and loss; jayājayau = both victory and defeat; tataḥ = thereafter; yuddhāya = for the sake of fighting; yujyasva = engage (fight); na = never; evaṃ = in this way; pāpaṃ = sinful reaction; avāpsyasi = you will gain.;