Valmiki Ramayana Kishkindha Kanda Sarga 11 Shloka 53
Original Shlokaइह तेनाप्रवेष्टव्यं प्रविष्टस्य वधो भवेत्। वनं मत्संश्रयं येन दूषितं रुधिरस्रवैः4.11.53।।
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मत्संश्रयम् under my protection, वनम् forest, येन by whom, रुधिरस्रवैः with drops of blood, दूषितम् is violated, तेन by him, इह here, न प्रवेष्टव्यम् should not enter, प्रविष्टस्य of him who enters, वधः death, भवेत् will take place.
'Whoever has desecrated this forest, protected by me, with drops of blood is forbidden to enter this place. Once he does it, he will die.