'First born' in the Bible

And thou shalt say to Pharaoh, Thus saith the LORD, Israel is my son, even my first-born.

And I say to thee, Let my son go, that he may serve me: and if thou shalt refuse to let him go, behold, I will slay thy son, even thy first-born.

These are the heads of their father's houses: The sons of Reuben the first-born of Israel; Hanoch, and Pallu, Hezron, and Carmi: these are the families of Reuben.

And all the first-born in the land of Egypt shall die, from the first-born of Pharaoh that sitteth upon his throne, even to the first-born of the maid-servant that is behind the mill; and all the first-born of beasts.

For I will pass through the land of Egypt this night, and will smite all the first-born in the land of Egypt, both man and beast: and against all the gods of Egypt I will execute judgment: I am the LORD.

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

Sanctify to me all the first-born, whatever openeth the womb among the children of Israel, both of man and of beast: it is mine.

And every firstling of an ass thou shalt redeem with a lamb; and if thou wilt not redeem it, then thou shalt break his neck: and all the first-born of man among thy children shalt thou redeem.

And it came to pass, when Pharaoh would hardly let us go, that the LORD slew all the first-born in the land of Egypt, both the first-born of man, and the first-born of beasts: therefore I sacrifice to the LORD all that openeth the matrix, being males; but all the first-born of my children I redeem.

Thou shalt not delay to offer the first of thy ripe fruits, and of thy liquors: the first-born of thy sons shalt thou give to me.

Every first-born is mine: and every firstling among thy cattle, whether ox or sheep, that is male.

But the firstling of an ass thou shalt redeem with a lamb: and if thou shalt not redeem him, then shalt thou break his neck. All the first-born of thy sons thou shalt redeem. And none shall appear before me empty.