Zevachim 31 - When do Thoughts Mix
Concerning the intent to eat an olive's volume piece of a sacrifice at the wrong time, and another piece in the wrong place , was the precise language "a piece, a piece" or "a piece and a piece?" Perhaps only in "a piece, a piece" the first thought is separate from the second, but in "a piece and a piece" the intents mix together and thus do not count?
We can learn the answer from what Levi asked of Rabbi Yehudah the Prince. Levi asked, "If one plans to eat a piece tomorrow in the wrong place, what is the law?" Previously Rabbi Yehudah taught other students two versions, with "and" and without, so they knew the answer. Levi, however, got only one version, without "and," so he devised the question that would tell him both answers. If Rabbi Yehudah is annoyed, it means that Levi could have found the answer himself and that Levi's version was the correct one. But Rabbi Yehudah answered calmly, "It is a mixture of thoughts." Now Levi knew both the answer to his question and that "a piece and a piece" was the correct version.
Art: Pieter Claesz - A Still Life With An Overturned Silver Tazza, A Silver Plate With A Partly Peeled Lemon And An Olive, With Walnuts And Hazelnuts