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 not work..." — It was taught: I know only an ox with regard to work and a sheep with regard to shearing; from where do I apply the stated restriction of each to the other? From the verse "you shall not work and you shall not shear."
On the daf / in context: The prohibitions of work and shearing are cross-applied: one may neither work nor shear either a firstborn ox or a firstborn sheep.
Type of Learning
Derash on the verse (Chullin) — cross-application of the work and shearing prohibitions.
What Is Learned
One may neither work with nor shear the firstborn of either cattle or flock.