'First born' in the Bible

The genealogies of the descendants of Reuben, the firstborn of Israel, were recorded individually, according to their tribes and ancestral houses, as were the names of all the men 20 years and above who could serve in the army.

The sons of Aaron were Nadab the first-born, Abihu, Eleazar, and Ithamar

"I'm taking the descendants of Levi for myself from among the Israelis in place of every first-born who opens the womb. The descendants of Levi belong to me

because all the first-born belong to me. When I destroyed all the firstborn in the land of Egypt, I consecrated all the first-born in Israel for myself from human beings to livestock. They belong to me, since I am the LORD."

Later the LORD instructed Moses: "Number all the first-born males of Israel from a month old and above and list their names.

Separate the descendants of Levi for me since I am the LORD in place of all the first-born sons of Israel. Also separate the livestock of the descendants of Levi in place of all the firstborn of the livestock of Israel."

So Moses numbered all the firstborn from the sons of Israel just as the LORD commanded him.

All the first-born males according to the list of their names from a month old and above numbered 22,273.

"Separate the descendants of Levi in place of all the firstborn sons of Israel and the livestock of the descendants of Levi in place of their livestock. The descendants of Levi belong to me, since I am the LORD.

You are to pay a ransom for the 273 first-born Israelis who exceed the census number of the descendants of Levi,

From the firstborn of the Israelis, Moses took money amounting to 1,365 shekels according to the shekel of the sanctuary.

since they've been set apart for me from among the Israelis. I've taken them for myself instead of the first to open the womb every firstborn of the Israelis,

since every firstborn of Israel belongs to me, from human beings to livestock. On the same day that I destroyed all the firstborn in the land of Egypt, I consecrated them to myself,

taking the descendants of Levi instead of every firstborn of the Israelis.

Everything that opens the womb, any living thing that they bring to the LORD whether from human beings or animals are for you. Just be sure that you redeem the firstborn of people and the firstborn of unclean animals.

But you are not to redeem the firstborn of a cow, sheep, or a female goat. They are holy. You are to sprinkle their blood on the altar and burn their fat for an offering made by fire, a pleasing aroma to the LORD.

From Reuben, Israel's firstborn, the descendants of Reuben included from Hanoch, the family of the descendants of Hanoch; from Pallu, the family of the descendants of Pallu;

while they were burying their firstborn, whom the LORD had killed among them. The LORD also executed justice against their gods.