Valmiki Ramayana Ayodhya Kanda Sarga 64 Shloka 20

अज्ञानात् by my ignorance, सहसा suddenly, भवतः पुत्रः your son, मया by me, निहतः was slain, एवं गते when this has happened, यत् whatever, शेषं स्यात् remains to be done, तत् that, मुनिः ascetic, प्रसीदतु be pleased.

Your son has been killed by me due to my ignorance. Since this has happened, may the ascetic be pleased to command me on the next course of action.