Exodus 22:28-31 - Regulations Regarding Tribute And Holiness
28 Thou shalt not revile the judges, nor curse a prince amongst thy people.
29 Thou shalt not delay the fulness of thy threshing-floor and the outflow of thy winepress. The firstborn of thy sons shalt thou give unto me. 30 Likewise shalt thou do with thy calf, with thy sheep: seven days shall it be with its dam; on the eighth day thou shalt give it me.
31 And ye shall be holy men unto me; and ye shall not eat flesh torn in the field: ye shall cast it to the dog.