Valmiki Ramayana Aranya Kanda Sarga 10 Shloka 15

राघव Rama, तपः penance, नित्यम् always, बहुविघ्नम् is full of obstacles, दुश्चरं चैव but is difficult to pursue, तेन therefore, राक्षसैः by demons, भक्ष्यमाणाः even if they eat us, शापम् curse, न not, मुञ्चामः we do not pronounce.

'O Rama it is difficult to perform penance which is ever full of obstacles. Therefore, we do not pronounce curses even if eaten up by demons'.