Canto 3 -
Araṇya-kāṇḍa
Chapter 50: Jaṭāyu Challenges Rāvaṇa
Text 3.50.18

यत्कृत्वा न भवेद्धर्मो न कीर्तिर्न यशो भुवि।
शरीरस्य भवेत्खेदः कस्तत्कर्म समाचरेत्॥

yat kṛtvā na bhaved dharmo na kīrtir na yaśo bhuvi
śarīrasya bhavet khedaḥ kas tat karma samācaret

yat = which; kṛtvā = by doing; na bhavet = one does not attain; dharmaḥ = pious credits; na kīrtiḥ = fame due to opulences; na yaśaḥ = or reputation as an enjoyer; bhuvi = on earth; śarīrasya = bodily; bhavet khedaḥ = and by which one attains distress; kaḥ = who; tat = that; karma = activity; samācaret = will carry out.

Who will carry out that activity by doing which one does not attain pious credits, fame due to opulences, or reputation as an enjoyer on earth, and by which one attains bodily distress?

Only a fool would carry out [such an activity]. Jaṭāyu implies that Rāvaṇa is such a fool because he is engaged in carrying out such an activity.

In the next two verses, Jaṭāyu tells Rāvaṇa, “Don’t insult me, considering me old.”