Manusmriti
किं चिदेव तु विप्राय दद्यादस्थिमतां वधे । अनस्थ्नां चैव हिंसायां प्राणायामेन शुध्यति ॥ १४१ ॥
But for killing (small) animals which have bones, he should give some trifle to a Brahmana; if he injures boneless (animals), he becomes pure by a suppressing his breath (pranayama).
english translation
kiM cideva tu viprAya dadyAdasthimatAM vadhe । anasthnAM caiva hiMsAyAM prANAyAmena zudhyati ॥ 141 ॥
hk transliteration by Sanscript