Strong's numbers

בְּכוֹר (H1060)

bᵉkôwr

bek-ore'

from בָּכַר; firstborn; hence, chief; eldest (son), firstborn(-ling).

בְּכוֹר 122 n.m. first-born

1 men and women

2 animals

3 figurative

From Brown, Driver, and Briggs, A Hebrew and English Lexicon of the Old Testament (1906), in the public domain.

Shown in the King James Version (KJV), whichever translation you read in — it is the text these numbers are tagged against.

Psalms 135:8
Who smote the firstborn of Egypt, both of man and beast.
Psalms 136:10
To him that smote Egypt in their firstborn: for his mercy endureth for ever:
Isaiah 14:30
And the firstborn of the poor shall feed, and the needy shall lie down in safety: and I will kill thy root with famine, and he shall slay thy remnant.
Jeremiah 31:9
They shall come with weeping, and with supplications will I lead them: I will cause them to walk by the rivers of waters in a straight way, wherein they shall not stumble: for I am a father to Israel, and Ephraim is my firstborn.
Micah 6:7
Will the LORD be pleased with thousands of rams, or with ten thousands of rivers of oil? shall I give my firstborn for my transgression, the fruit of my body for the sin of my soul?
Zechariah 12:10
And I will pour upon the house of David, and upon the inhabitants of Jerusalem, the spirit of grace and of supplications: and they shall look upon me whom they have pierced, and they shall mourn for him, as one mourneth for his only son, and shall be in bitterness for him, as one that is in bitterness for his firstborn.