Canto 3 -
Araṇya-kāṇḍa
Chapter 53: Sītā Chastises Rāvaṇa
Text 3.53.8

कथयिष्यन्ति लोकेषु पुरुषाः कर्म कुत्सितम्।
सुनृशंसमधर्मिष्ठं तव शौण्डीर्यमानिनः॥

kathayiṣyanti lokeṣu puruṣāḥ karma kutsitam
sunṛśaṁsam adharmiṣṭhaṁ tava śauṇḍīrya-māninaḥ

kathayiṣyanti = will proclaim; lokeṣu = in [all] the worlds; puruṣāḥ = [but] people; karma = this act; kutsitam = as being condemned; sunṛśaṁsam = extremely cruel; adharmiṣṭham = and most adhārmika; tava = of yours; śauṇḍīrya-māninaḥ = you consider yourself to be a hero.

You consider yourself to be a hero [but] people in [all] the worlds will proclaim this act of yours as being condemned, extremely cruel and most adhārmika.