'First born' in the Bible

Canaan became the father of Sidon, his firstborn, and Heth

Then the firstborn said to the younger, “Our father is old, and there is not a man on earth to come in to us after the manner of the earth.

So they made their father drink wine that night, and the firstborn went in and lay with her father; and he did not know when she lay down or when she arose.

On the following day, the firstborn said to the younger, “Behold, I lay last night with my father; let us make him drink wine tonight also; then you go in and lie with him, that we may preserve our family through our father.”

The firstborn bore a son, and called his name Moab; he is the father of the Moabites to this day.

Uz 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, in the order of their birth: Nebaioth, the firstborn of Ishmael, and Kedar and Adbeel and Mibsam

Jacob said to his father, “I am Esau your firstborn; I have done as you told me. Get up, please, sit and eat of my game, that you may bless me.”

Isaac his father said to him, “Who are you?” And he said, “I am your son, your firstborn, Esau.”

But Laban said, “It is not the practice in our place to marry off the younger before the firstborn.

the sons of Leah: Reuben, Jacob’s firstborn, then Simeon and Levi and Judah and Issachar and Zebulun;

These are the chiefs of the sons of Esau. The sons of Eliphaz, the firstborn of Esau, are chief Teman, chief Omar, chief Zepho, chief Kenaz,

Now Judah took a wife for Er his firstborn, and her name was Tamar.

But Er, Judah’s firstborn, was evil in the sight of the Lord, so the Lord took his life.

Joseph named the firstborn Manasseh, “For,” he said, “God has made me forget all my trouble and all my father’s household.”

Now they were seated before him, the firstborn according to his birthright and the youngest according to his youth, and the men looked at one another in astonishment.

Now these are the names of the sons of Israel, Jacob and his sons, who went to Egypt: Reuben, Jacob’s firstborn.

But Israel stretched out his right hand and laid it on the head of Ephraim, who was the younger, and his left hand on Manasseh’s head, crossing his hands, although Manasseh was the firstborn.

Joseph said to his father, “Not so, my father, for this one is the firstborn. Place your right hand on his head.”

“Reuben, you are my firstborn;My might and the beginning of my strength,Preeminent in dignity and preeminent in power.