Tosefta para sa Deuteronomio 17:2

[If] the community and the Kohanim are pure and the service vessels are impure, they perform it (i.e., the slaughter of the Passover offering) in a state of impurity. At what time may the Passover offering be brought in a state of impurity? At any time that the majority of the community is impure. [If] half was pure and half was impure, the pure [half] observe Pesach Rishon and the impure [half] observe Pesach Sheni. [However,] an individual may tip the balance (i.e., he may intentionally make himself impure, thereby creating an impure majority (Pes. 80a:4)), in order [for the entire community] to observe [the first] Passover in a state of impurity, the words of Rabbi Yehuda. Rabbi Eliezer ben Metatyah says, an individual may not [intentionally] tip the balance in order [for the entire community] to observe [the first] Passover in a state of impurity, as it says (Deut. 16:5), "You may not slaughter the Passover offering in one of your settlements" (see Y. Pes. VIII.7.2). Rabbi Shimon says, [if there are] half pure and half impure, the pure perform [the Passover offering] amongst themselves, and the impure perform amongst themselves. They said to him, they may not divide the community; rather, either everyone performs it in a state of purity, or everyone performs it a state of impurity.