TSK · Numbers 3:13

Sanctify unto me all the firstborn, whatsoever openeth the womb among the children of Israel, [both] of man and of beast: it [is] mine.

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.

All that openeth the matrix [is] mine; and every firstling among thy cattle, [whether] ox or sheep, [that is male].

And thou shalt take the Levites for me (I [am] the LORD) instead of all the firstborn among the children of Israel; and the cattle of the Levites instead of all the firstlings among the cattle of the children of Israel.

And I, behold, I have taken your brethren the Levites from among the children of Israel: to you [they are] given [as] a gift for the LORD, to do the service of the tabernacle of the congregation.

For the Egyptians buried all [their] firstborn, which the LORD had smitten among them: upon their gods also the LORD executed judgments.

(As it is written in the law of the Lord, Every male that openeth the womb shall be called holy to the Lord;)