Exodus:22:29-30
dby@Exodus:22:29 @ -- 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.
dby@Exodus:22:30 @ 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.