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
Every firstborn of a donkey you shall redeem with a lamb; and if you will not redeem it, then you shall break its neck; and you shall redeem all the firstborn of man among your sons.
Exodus 34:20
The firstborn of a donkey you shall redeem with a lamb: and if you will not redeem it, then you shall break its neck. All the firstborn of your sons you shall redeem. No one shall appear before me empty.
Leviticus 27:27
If it is an unclean animal, then he shall buy it back according to your valuation, and shall add to it the fifth part of it: or if it isn't redeemed, then it shall be sold according to your valuation.

General references

Numbers 3:15
"Count the children of Levi by their fathers' houses, by their families. You shall count every male from a month old and upward."