A verse from Vayikra 21:6 is cited to demonstrate that if a tvul yom - someone who has immersed in a mikveh but must wait until sunset to complete their purification - performs one of the essential sacrificial rites, the sacrifice is invalidated. The discussion explores how this verse specifically refers to a tvul yom and not another form of impurity.

The Mishna lists three distinct categories: an impure person, a tvul yom, and a mechusar kaparah - someone who has completed immersion and sunset but still needs to bring a sacrificial offering (e.g., a zav on the eighth day of his purification). The necessity of listing all three is examined, highlighting the unique halachic implications of each status.

Sources are brought to prove that if a kohen performs sacrificial rites without wearing all the required priestly garments, the sacrifice is disqualified.