Exodus 13:12 That thou shalt set apart unto the LORD all that openeth the matrix, and every firstling that cometh of a beast which thou hast; the males shall be the LORD's. (KJV WBS)
Exodus 13:15 And it came to pass, when Pharaoh would hardly let us go, that the LORD slew all the firstborn in the land of Egypt, both the firstborn of man, and the firstborn of beast: therefore I sacrifice to the LORD all that openeth the matrix, being males; but all the firstborn of my children I redeem. (KJV WBS)
Exodus 34:19 All that openeth the matrix is mine; and every firstling among thy cattle, whether ox or sheep, that is male. (KJV)
Numbers 3:12 And I, behold, I have taken the Levites from among the children of Israel instead of all the firstborn that openeth the matrix among the children of Israel: therefore the Levites shall be mine; (KJV WBS)