More on the pinching of the bird - melikah. If done in ways that were considered inappropriate or incongruous (like, at night), then the melikah would be invalid, but without rendering anything impure - not even the clothing of the kohen. Plus, the newly introduced term of a "treyfah," but the definition is yet to come. How does the proper slaughter of a treyfah prevent the impurity that accompanies a "neveilah," carcass?