Numbers 3:13

for all the first-born are mine. On the day that I smote all the first-born in the land of Egypt I hallowed to me all the first-born in Israel, both man and beast. They shall be mine. I am LORD.

Exodus 13:2

Sanctify to me all the first-born, whatever opens the womb among the sons of Israel. Both of man and of beast, it is mine.

Exodus 13:12

that thou shall set apart to LORD all that opens the womb. And every firstling which thou have that comes of a beast, the males shall be LORD's.

Exodus 13:15

And it came to pass, when Pharaoh would hardly let us go, that LORD slew all the first-born in the land of Egypt, both the first-born of man, and the first-born of beast. Therefore I sacrifice to LORD all that opens the womb, being

Leviticus 27:26

Only the firstling among beasts, which is made a firstling to LORD, no man shall sanctify it, whether it be ox or sheep, it is LORD's.

Exodus 12:29-30

And it came to pass at midnight, that LORD smote all the first-born in the land of Egypt, from the first-born of Pharaoh who sat on his throne to the first-born of the captive who was in the dungeon, and all the first-born of cattl

Exodus 22:29

Thou shall not delay to offer from thy harvest, and from the outflow of thy presses. The first-born of thy sons thou shall give to me.

Exodus 34:19

All that opens the womb is mine, and all thy cattle that is male, the firstlings of cow and sheep.

Numbers 8:16-17

For they are wholly given to me from among the sons of Israel; instead of all who open the womb, even the first-born of all the sons of Israel, I have taken them to me.

Numbers 18:15

Everything that opens the womb, of all flesh which they offer to LORD, both of man and beast shall be thine. Nevertheless the first-born of man thou shall surely redeem, and the firstling of unclean beasts thou shall redeem.

Ezekiel 44:30

And the first of all the first-fruits of every thing, and every oblation of everything, of all your oblations, shall be for the priest. Ye shall also give to the priests the first of your dough, to cause a blessing to rest on thy h

Luke 2:23

(just as it is written in a law of Lord that every male that opens a womb will be called holy to the Lord),

Hebrews 12:23

to a festal gathering and assembly of firstborn sons who were enrolled in the heavens, and to God, a Judge of all, and to spirits of righteous men who were made fully perfect,

Treasury of Scripture Knowledge

Summary

Because all the firstborn are mine; for on the day that I smote all the firstborn in the land of Egypt I hallowed unto me all the firstborn in Israel, both man and beast: mine shall they be: I am the LORD.

Bible References

Because

Numbers 8:16
For they are wholly given to me from among the sons of Israel; instead of all who open the womb, even the first-born of all the sons of Israel, I have taken them to me.
Numbers 18:15
Everything that opens the womb, of all flesh which they offer to LORD, both of man and beast shall be thine. Nevertheless the first-born of man thou shall surely redeem, and the firstling of unclean beasts thou shall redeem.
Exodus 13:2
Sanctify to me all the first-born, whatever opens the womb among the sons of Israel. Both of man and of beast, it is mine.
Exodus 22:29
Thou shall not delay to offer from thy harvest, and from the outflow of thy presses. The first-born of thy sons thou shall give to me.
Exodus 34:19
All that opens the womb is mine, and all thy cattle that is male, the firstlings of cow and sheep.
Leviticus 27:26
Only the firstling among beasts, which is made a firstling to LORD, no man shall sanctify it, whether it be ox or sheep, it is LORD's.
Ezekiel 44:30
And the first of all the first-fruits of every thing, and every oblation of everything, of all your oblations, shall be for the priest. Ye shall also give to the priests the first of your dough, to cause a blessing to rest on thy h
Luke 2:23
(just as it is written in a law of Lord that every male that opens a womb will be called holy to the Lord),
Hebrews 12:23
to a festal gathering and assembly of firstborn sons who were enrolled in the heavens, and to God, a Judge of all, and to spirits of righteous men who were made fully perfect,

On the day

Exodus 12:29
And it came to pass at midnight, that LORD smote all the first-born in the land of Egypt, from the first-born of Pharaoh who sat on his throne to the first-born of the captive who was in the dungeon, and all the first-born of cattl
Exodus 13:15
And it came to pass, when Pharaoh would hardly let us go, that LORD slew all the first-born in the land of Egypt, both the first-born of man, and the first-born of beast. Therefore I sacrifice to LORD all that opens the womb, being