English: "Any serious blemish" — I know only one that was born perfect and later became blemished; from where do I include one that was born blemished from its mother’s womb? From the verse "any serious blemish."
On the daf / in context: A firstborn that is born with a congenital defect is equally disqualified from the altar.
Type of Learning
Derash on the verse (Bekhoros) — congenital blemishes also disqualify.
What Is Learned
A firstborn born with a blemish is disqualified from the altar just as one that acquires a blemish later.