'Firstling' in the Bible

You shall redeem the firstborn of a donkey with a lamb; but if you do not redeem it, then you shall break its neck. You shall redeem all the firstborn of your sons. None of you are to appear before Me empty-handed.

‘However, the firstborn among animals, which as a firstborn belongs to the Lord, no man may consecrate, whether an ox or a sheep. It is [already] the Lord’s.

Every firstborn of the womb of all flesh, whether it is man or animal, which they bring to the Lord, shall be yours; nevertheless, the firstborn of man you shall most certainly redeem, and the firstborn of unclean animals you shall redeem.

But the firstborn of a cow or of a sheep or of a goat you shall not redeem; they are holy [and belong to the Lord]. You shall sprinkle their blood on the altar and shall offer up their fat in smoke as an offering by fire, for a sweet and soothing aroma to the Lord.

“You shall consecrate (set apart) to the Lord your God all the firstborn males that are born of your herd and flock. You shall not work with the firstborn of your herd, nor shear the firstborn of your flock.

“His majesty is like a firstborn young bull,And his horns like the horns of the wild ox;With them he will gore the peoples,All of them together, to the ends of the earth.And those are the ten thousands of Ephraim,And those are the thousands of Manasseh.”