Valmiki Ramayana Kishkindha Kanda Sarga 18 Shloka 22
Original Shlokaन हि ते मर्षये पापं क्षत्रियोऽहं कुलोद्भवः। औरसीं भगिनीं वापि भार्यां वाप्यनुजस्य यः4.18.22।। प्रचरेत नरः कामात्तस्य दण्डो वधः स्मृतः।
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कुलोद्भव: born in a good family, क्षत्रियः kshatriya, अहम् I am, ते your, पापम् sin, न मर्षये I will not pardon, यः नरः whoever, औरसीम् his own daughter, भगिनीं वापि even sister also, अनुजस्य brother's, भार्यां वापि wife also, कामात् out of lust, प्रचरेत meets, तस्य his, दण्डः punishment, वधः killing, स्मृतः ordained in scriptures.
'I am a kshatriya born of a good family. I will not pardon you for your sin. Whosoever transgresses dharma against his own daughter, sister or brother's wife out of lust should be killed according to smriti.