(Mishnah): The appointee told them "go see if the time for Shechitah arrived.'' If it came, the one who sees says "Borkai.'' Masyah ben Shmuel says, "did the entire eastern sky until Chevron light up?'', and he says "yes''.

What [does he say]? Borkai Barekes (the illuminator is illuminating);

There (in Bavel), they say [that he says] Berok Berokah, the illuminator is illuminating.

Question: Is one witness believed [about this]?

Answer: Here is different, for [others] can know. He fears to say until light comes out, for there is a Chachmah to the matter (if he saw above, it should be visible below very soon. People are not suspected to lie about matters prone to become known. We explained that this is all one answer, like R. CHANANEL.)

If one witness said that Ploni was born on Shabbos, we circumcise him on [the next] Shabbos, based on his words. [If one witness said that] it became dark on Motza'ei Shabbos, we may move things [in Reshus ha'Rabim - HA'GAON RAV C. KANIEVSKY, SHLITA] based on him.

Note: The same should apply to any Melachah! Why does it specify Hotza'ah? I did not see anyone say that he would not carry only in Karmelis, but not in Reshus ha'Rabim mid'Oraisa.

R. Imi would carry based on women who drew water (on Erev Shabbos in a high place, and see that the sun did not set yet). R. Matanyah would carry based on farmers of Zahara (a place, even though they lack Chezkas Kashrus). R. Ami would circumcise [on Shabbos] based on women in a high place who said that the sun did not set yet (when the baby was born on Shabbos)

Question: Why does he say "until Chevron'', and he says "yes''?

Answer: He comes to mention merit of the Avos.