'First born' in the Bible

And Abel also presented an offering—some of the firstborn of his flock and their fat portions. The Lord had regard for Abel and his offering,

And Canaan begat Sidon his firstborn, and Heth,

After Terah had lived seventy years, he became the father of Abram and Nahor and Haran [his firstborn].

And the firstborn said unto the younger, Our father is old, and there is not a man in the earth to come in unto us after the manner of all the earth:

And they made their father drink wine that night: and the firstborn went in, and lay with her father; and he perceived not when she lay down, nor when she arose.

And it came to pass on the morrow, that the firstborn said unto the younger, Behold, I lay yesternight with my father: let us make him drink wine this night also; and go thou in, and lie with him, that we may preserve seed of our father.

And the firstborn bare a son, and called his name Moab: the same is the father of the Moabites unto this day.

Huz his firstborn, and Buz his brother, and Kemuel the father of Aram,

And these are the names of the sons of Ishmael, by their names, according to their generations: the firstborn of Ishmael, Nebajoth; and Kedar, and Adbeel, and Mibsam,

Jacob answered, “First sell me your birthright (the rights of a firstborn).”

and make me a savory and delicious dish [of meat], the kind I love, and bring it to me to eat, so that my soul may bless you [as my firstborn son] before I die.”

And Jacob said unto his father, I am Esau thy firstborn; I have done according as thou badest me: arise, I pray thee, sit and eat of my venison, that thy soul may bless me.

And Isaac his father said unto him, Who art thou? And he said, I am thy son, thy firstborn Esau.

And Laban said, It must not be so done in our country, to give the younger before the firstborn.

The sons of Leah; Reuben, Jacob's firstborn, and Simeon, and Levi, and Judah, and Issachar, and Zebulun:

These were dukes of the sons of Esau: the sons of Eliphaz the firstborn son of Esau; duke Teman, duke Omar, duke Zepho, duke Kenaz,

And Judah took a wife for Er his firstborn, whose name was Tamar.

And Er, Judah's firstborn, was wicked in the sight of the LORD; and the LORD slew him.

And Joseph called the name of the firstborn Manasseh: For God, said he, hath made me forget all my toil, and all my father's house.

And they sat before him, the firstborn according to his birthright, and the youngest according to his youth: and the men marvelled one at another.

And these are the names of the children of Israel, which came into Egypt, Jacob and his sons: Reuben, Jacob's firstborn.

And Israel stretched out his right hand, and laid it upon Ephraim's head, who was the younger, and his left hand upon Manasseh's head, guiding his hands wittingly; for Manasseh was the firstborn.

And Joseph said unto his father, Not so, my father: for this is the firstborn; put thy right hand upon his head.

Reuben, thou art my firstborn, my might, and the beginning of my strength, the excellency of dignity, and the excellency of power:

“But unstable and reckless and boiling over like water [in sinful lust], you shall not excel or have the preeminence [of the firstborn],Because you went up to your father’s bed [with Bilhah];You defiled it—he went up to my couch.