Exodus:34:19-20
vw@Exodus:34:19 @ Everything that opens the womb is Mine, and every male firstborn among your livestock, whether ox or sheep.
vw@Exodus:34:20 @ But the firstborn of a donkey you shall redeem with a lamb. And if you will not redeem him, then you shall break his neck. All the firstborn of your sons you shall redeem. And no one shall appear before Me empty.