Leviticus 27:26

But no one may consecrate a firstborn of the livestock, because a firstborn belongs to the Lord. Whether it is an ox or a sheep, it is the Lord’s.

Only the firstling of the beasts, which should be the Lord’s firstling, no man shall sanctify it; whether it be ox, or sheep: it is the Lord’s.

Note firstling of: Heb. firstborn, etc

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

Only the firstling among beasts, which is made a firstling to Jehovah, no man shall sanctify it; whether it be ox or sheep, it is Jehovah’s.