Every firstborn that is born in your herd and in your flock, the male, you shall consecrate to Hashem your God; you shall not work with the firstborn of your ox, nor shear the firstborn of your flock.
English: "You shall consecrate to Hashem" — It was taught: From where do we know that when a firstborn is born in one’s flock there is a mitzvah to consecrate it? From the verse "every firstborn that is born you shall consecrate to Hashem."
On the daf / in context: Although a firstborn is automatically sacred, there is an additional positive commandment to declare its sanctity verbally.
Type of Learning
Derash on the verse (Bekhoros) — a positive mitzvah to declare the firstborn sacred.
What Is Learned
There is a positive commandment to verbally consecrate a firstborn animal that is born in one’s flock.