Mishnah/Seder Moed/Tractate Rosh Hashanah/Chapter 1/5
Seder Moed, Tractate Rosh Hashanah: Chapter 1, Mishnah 5
Continuing the previous mishnah, this mishnah reflects the disparity of different rabbis on how important it was that people come to Jerusalem to say that they saw the new moon.
Hebrew Text 
- בין שנראה בעליל, בין שלא נראה בעליל,
- מחללין עליו את השבת;
- רבי יוסי אומר,
- אם נראה בעליל, אין מחללין עליו את השבת.
English Translation 
- Regardless of whether the moon was clearly visible or not clearly visible,
- They desecrate the Shabbat for it;
- Rabbi Yosei says:
- If it was clearly visible, they do not desecrate the Shabbat for it.
They desecrate the Shabbat for it: The Sages believe that it is acceptable to desecrate Shabbat regardless of whether or not the moon was seen clearly, reasoning that the weather in Jerusalem may be different from the weather in a different area.
They do not desecrate the Shabbat for it: Rabbi Yosei holds the opposing view to that of the Sages, that the weather is more than likely the same and that, thus, desecrating Shabbat is not necessary if it is a clear night. His view is not followed in practice, however.