Numbers 18:15

Everything that breaketh open the womb of all flesh, which they present to Jehovah, of men or of beasts, shall be thine; nevertheless the firstborn of man shalt thou in any case ransom, and the firstborn of unclean beasts shalt thou ransom.

Exodus 34:20

But the firstling of an ass thou shalt ransom with a lamb; and if thou ransom it not, then shalt thou break its neck. All the first-born of thy sons thou shalt ransom; and none shall appear before me empty.

Exodus 13:2

Hallow unto me every firstborn, whatever breaketh open the womb among the children of Israel, of man and of cattle: it is mine.

Exodus 13:12-13

that thou shalt offer unto Jehovah all that breaketh open the womb, and every firstling that cometh of cattle which is thine: the males shall be Jehovah's.

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.

Leviticus 27:26-27

Only the firstling which is offered as firstling to Jehovah among the cattle, that shall no man hallow, whether it be ox or sheep; it is Jehovah's.

Numbers 3:13

for every firstborn is mine. On the day that I smote all the firstborn in the land of Egypt, I hallowed unto me all the firstborn in Israel, both of man and beast; mine shall they be: I am Jehovah.

Numbers 3:46

And for those that are to be ransomed, the two hundred and seventy-three of the firstborn of the children of Israel, which are in excess over the Levites,

Treasury of Scripture Knowledge

Summary

Every thing that openeth the matrix in all flesh, which they bring unto the LORD, whether it be of men or beasts, shall be thine: nevertheless the firstborn of man shalt thou surely redeem, and the firstling of unclean beasts shalt thou redeem.

General references

Bible References

The firstborn

Exodus 13:13
And every firstling of an ass shalt thou ransom with a lamb; and if thou do not ransom it, thou shalt break its neck; and every firstborn of a man among thy sons shalt thou ransom.
Exodus 34:20
But the firstling of an ass thou shalt ransom with a lamb; and if thou ransom it not, then shalt thou break its neck. All the first-born of thy sons thou shalt ransom; and none shall appear before me empty.
Leviticus 27:27
But if it be of an unclean beast, then he shall ransom it according to thy valuation, and shall add a fifth of it thereto; and if it be not redeemed, it shall be sold according to thy valuation.

General references

Numbers 3:15
Number the sons of Levi according to their fathers' houses, after their families; every male from a month old and upward shalt thou number them.