Manava Dharmashastra 5.31

5.31

yajñāya jagdhir māṃsasyety eṣa daivo vidhiḥ smṛtaḥ
ato 'nyathā pravṛttis tu rākṣaso vidhir ucyate //

'The consumption of meat (is befitting) for sacrifices,' that is declared to be a rule made by the gods; but to persist (in using it) on other (occasions) is said to be a proceeding worthy of Rakshasas.