Valmiki Ramayana Bala Kanda Sarga 2 Shloka 28
Original Shlokaपापात्मना कृतं कष्टं वैरग्रहणबुद्धिना । यस्तादृशं चारुरवं क्रौञ्चं हन्यादकारणात् ।।1.2.28।।
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य: that hunter, तादृशम् such, चारुरवम् sweet voiced, क्रौञ्चम् krauncha bird, अकारणात् without cause, हन्यात् killed, वैरग्रहणबुद्धिना with hostile feeling of capturing it, पापात्मना sinful minded, कष्टं(कर्म) act, कृतम् was done.
The hunter killed the sweetvoiced krauncha without any cause. That sinfulminded one with hostile feeling of capturing it, had perpetrated this cruel act, he thought.