Valmiki Ramayana Sundara Kanda Sarga 52 Shloka 20
Original Shlokaसाधुर्वा यदि वाऽसाधुः परैरेष समर्पितः। ब्रुवन् परार्थं परवान्न दूतो वधमर्हति।।5.52.20।।
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साधुर्वा may be soft, असाधुर्यदि वा or hard, एषः he, परैः by others, समर्पितः sent, परार्थम् by others, ब्रुवन् while speaking, परवान् he is dependent, दूतः emissary, वधम् killing, न अर्हति does not deserve.
"Whether he is soft or harsh, he has been sent by others. He is speaking on other's behalf and is dependent on them. An emissary does not deserve to be killed.