My lord, you are completely aware of the religious principles. As a son never deserves to be killed by his father, here is a brāhmaṇa who should be protected by the king, and never killed. How does he deserve to be killed by a rājarṣi like you?
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
सोऽयं ब्रह्मर्षिवर्यस्ते राजर्षिप्रवराद्विभो । कथमर्हति धर्मज्ञ वधं पितुरिवात्मजः
so'yaṃ brahmarṣivaryaste rājarṣipravarādvibho | kathamarhati dharmajña vadhaṃ piturivātmajaḥ
SB 9.9.30