Valmiki Ramayana Yuddha Kanda Sarga 83 Shloka 28

परन्तप scorcher of enemies, अथ now, सत्यवचनम् truthful words, धर्मःकिलचेत् if you consider as dharma, अनृतःuntruth, त्वयि you, अकरुणः not compassionate, पिता father, त्वया you, किम् why, न बद्धःdid not bind

"O scorcher of enemies! If you consider speaking the truth is dharma, why did you not bind your father (who promised to give the kingdom) and was not compassionate (spoke untruth later)."