Exodus 34:19 KJV
All that openeth the matrix is mine; and every firstling among thy cattle, whether ox or sheep, that is male.
Exodus 34:17–21 KJV Chapter Context
17
Thou shalt make thee no molten gods.
18
The feast of unleavened bread shalt thou keep. Seven days thou shalt eat unleavened bread, as I commanded thee, in the time of the month Abib: for in the month Abib thou camest out from Egypt.
19
All that openeth the matrix is mine; and every firstling among thy cattle, whether ox or sheep, that is male.
20
But the firstling of an ass thou shalt redeem with a lamb: and if thou redeem him not, then shalt thou break his neck. All the firstborn of thy sons thou shalt redeem. And none shall appear before me empty.
21
Six days thou shalt work, but on the seventh day thou shalt rest: in earing time and in harvest thou shalt rest.