And in the process of time it came to pass that Cain brought an offering of the fruit of the ground to the LORD. Abel also brought of the firstborn (bekorah) of his flock and of their fat. And the LORD respected Abel and his offering, but He did not respect Cain and his offering. Genesis 4:4.
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." (Genesis 27:19,32).
the sons of Leah: Reuben, Jacob's firstborn, and Simeon, Levi, Judah, Issachar, and Zebulun... (Genesis 35:23; cf. 46:8).
Joseph called the name of the firstborn Manasseh: "For God has made me forget all my toil and all my father's house." (Genesis 45:51; see 48:14.18).
And they sat before him, the firstborn according to his birthright (bekorah) and the youngest according to his youth; and the men looked in astonishment at one another. (Genesis 43:33).
Then you shall say to Pharaoh, "Thus says the LORD: 'Israel [is] My son, My firstborn.' So I say to you, let My son go that he may serve Me. But if you refuse to let him go, indeed I will kill your son, your firstborn. (Exodus 4:22-23).
Consecrate to Me all the firstborn, whatever opens the womb among the children of Israel, [both] of man and beast; it is Mine.... that you shall set apart to the LORD all that open the womb, that is, every firstborn that comes from an animal which you have; the males [shall be] the LORD's. But 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 all the firstborn of man among your sons you shall redeem... 'And it came to pass, when Pharaoh was stubborn about letting us go, that the LORD killed all the firstborn in the land of Egypt, both the firstborn of man and the firstborn of beast. Therefore I sacrifice to the LORD all males that open the womb, but all the firstborn of my sons I redeem.' (Exodus 13:2-15).
The firstborn of your sons you shall give to Me. (Exodus 22:29).
Now behold, I Myself have taken the Levites from among the children of Israel instead of every firstborn who opens the womb among the children of Israel. Therefore the Levites shall be Mine, because all the firstborn [are] Mine. On the day that I struck all the firstborn in the land of Egypt, I sanctified to Myself all the firstborn in Israel, both man and beast. They shall be Mine: I [am] the LORD." (Numbers 3:12-13).
Then the LORD said to Moses, "Number every firstborn male of the sons of Israel from a month old and upward, and make a list of their names. 41 "You shall take the Levites for Me, I am the LORD, instead of all the firstborn among the sons of Israel, and the cattle of the Levites instead of all the firstborn among the cattle of the sons of Israel." 42 So Moses numbered all the firstborn among the sons of Israel, just as the LORD had commanded him; 43 and all the firstborn males by the number of names from a month old and upward, for their numbered men were 22,273. 44 Then the LORD spoke to Moses, saying, 45 "Take the Levites instead of all the firstborn among the sons of Israel and the cattle of the Levites. And the Levites shall be Mine; I am the LORD. 46 "For the ransom of the 273 of the firstborn of the sons of Israel who are in excess beyond the Levites, 47 you shall take five shekels apiece, per head; you shall take them in terms of the shekel of the sanctuary (the shekel is twenty gerahs), 48 and give the money, the ransom of those who are in excess among them, to Aaron and to his sons." 49 So Moses took the ransom money from those who were in excess, beyond those ransomed by the Levites; 50 from the firstborn of the sons of Israel he took the money in terms of the shekel of the sanctuary, 1,365. 51 Then Moses gave the ransom money to Aaron and to his sons, at the command of the LORD, just as the LORD had commanded Moses. (Numbers 3:40-51).
Everything that first opens the womb of all flesh, which they bring to the LORD, whether man or beast, shall be yours; nevertheless the firstborn of man you shall surely redeem, and the firstborn of unclean animals you shall redeem. (NUmbers 18:15).
He will cry to Me, `You are my Father, My God, and the rock of my salvation.' 27 "I also shall make him My firstborn, The highest of the kings of the earth. 28 "My lovingkindness I will keep for him forever, And My covenant shall be confirmed to him. 29 "So I will establish his descendants forever And his throne as the days of heaven. (Psalm 89:26-29).
For I am a Father to Israel, And Ephraim [is] My firstborn. (Jeremiah 31:9; see Genesis 48:14-18).
Yes, they will mourn for Him as one mourns for his only son and grieve for Him as one grieves for a firstborn. (Zechariah 12:10).