Śvetadvīpa-varṇana and Śāstra-pravartana (Śānti Parva 322)
शकुनानामिवाकाशे मत्स्यानामिव चोदके । पद यथा न दृश्येत तथा पुण्यकृतां गति:
śakunānām ivākāśe matsyānām iva codake | padaṃ yathā na dṛśyeta tathā puṇyakṛtāṃ gatiḥ ||
Bhīṣma said: “Just as the footprints of birds are not seen in the sky, and the tracks of fish are not seen in water, so too the course and final destination of those who perform merit—the truly virtuous and wise—cannot be traced or known by ordinary observation.”
भीष्म उवाच
The verse teaches that the inner trajectory and ultimate destiny (gati) of truly meritorious, wise people cannot be reliably inferred from outward signs. Like birds in the sky or fish in water, their movement leaves no visible trace—urging humility in judging others and emphasizing the subtlety of karmic outcomes.
In Śānti Parva, Bhīṣma instructs Yudhiṣṭhira on dharma and right conduct after the war. Here he uses a vivid simile to explain that the workings and end-state of the virtuous are not easily knowable, reinforcing the broader didactic tone of counsel and moral reflection.