Verse 27

तदर्थं मा कृथा व्यर्थं विषादं मरणे पितुः ।अवश्यभाव्यस्तमयो जातस्याहर्षतेरिव

In plain words

"Therefore do not indulge useless grief over your father's death. For one who is born, setting is inevitable, as it is for the lord of the day."