कर्मण्यकर्म यः पश्येदकर्मणि च कर्म यः.।

it is the shlok of most popular epic caled bhagwat geeta.
As you know about world's biggest epic "Mahabharat". It is the true story between two families.

The meaning of this shlok is that- (in Mahabharata when Arjun sees his relatives standing against him,...