If the 14th of Nisan fell on Shabbat, the Korban Pesach was still sacrificed, but the Gemara asked the question about what happens if the person offering the sacrifice had improper intentions. Conversely, what happens when a person initially did not designate an animal to be a Korban Pesach, but then changes his mind. What is the status of the sacrifice in this scenario. A number of different opinions were brought in the Gemara, illustrating the lack of agreement regarding the power that human thought and intention had over the designation and status of sacrifices.
Rabbi Michael Pitkowsky is the Rabbinics Curriculum Coordinator at the Academy for Jewish Religion and an Adjunct Assistant Professor at the Jewish Theological Seminary of America. Michael lives in the Riverdale neighborhood of the Bronx with his wife and two children and is a member of CSAIR. He can be found blogging at menachemmendel.net/blog and on Twitter @mpitkowsky.