6בֵּית דִּין מְחַשְּׁבִין בְּחֶשְׁבּוֹנוֹת כְּדֶרֶךְ שֶׁמְּחַשְּׁבִים הָאִיצְטַגְנִינִים שֶׁיּוֹדְעִין מְקוֹמוֹת הַכּוֹכָבִים וּמַהֲלָכָם וְחוֹקְרִים וּמְדַקְדְּקִים עַד שֶׁיֵּדְעוּ אִם אֶפְשָׁר שֶׁיֵּרָאֶה הַיָּרֵחַ בִּזְמַנּוֹ שֶׁהוּא לֵיל שְׁלֹשִׁים אוֹ אִי אֶפְשָׁר. אִם יָדְעוּ שֶׁאֶפְשָׁר שֶׁיֵּרָאֶה יוֹשְׁבִין וּמְצַפִּין לָעֵדִים כָּל הַיּוֹם כֻּלּוֹ שֶׁהוּא יוֹם שְׁלֹשִׁים. אִם בָּאוּ עֵדִים וּדְרָשׁוּם וַחֲקָרוּם כַּהֲלָכָה וְנֶאֶמְנוּ דִּבְרֵיהֶם מְקַדְּשִׁין אוֹתוֹ. וְאִם לֹא נִרְאָה וְלֹא בָּאוּ עֵדִים מַשְׁלִימִין שְׁלֹשִׁים וְיִהְיֶה חֹדֶשׁ מְעֵבָּר. וְאִם יָדְעוּ בְּחֶשְׁבּוֹן שֶׁאִי אֶפְשָׁר שֶׁיֵּרָאֶה אֵין יוֹשְׁבִים יוֹם שְׁלֹשִׁים וְאֵין מְצַפִּין לָעֵדִים. וְאִם בָּאוּ עֵדִים יוֹדְעִין בְּוַדַּאי שֶׁהֵן עֵדֵי שֶׁקֶר אוֹ שֶׁנִּרְאֵית לָהֶם דְּמוּת לְבָנָה מִן הֶעָבִים וְאֵינָהּ הַלְּבָנָה הַוַּדָּאִית:
The [High] Court would make calculations in a manner resembling the calculations of the astronomers, who know the location of the stars and their paths [in their orbits]. They would perform careful research to determine whether or not they would be able to sight the moon at the appropriate time - i.e., the thirtieth night. If [the judges] determined that it was possible to sight [the moon], they would sit waiting for witnesses [to come and testify] throughout the entire thirtieth day. If witnesses came, and [the court] examined their testimony according to law, and verified the truth [of their statements], the court would sanctify [the new month]. If [the moon] was not sighted, and witnesses did not come, they would complete the thirtieth day, thus making the month full. If, according to their calculations, [the judges] knew that it was impossible for the moon to be sighted, they would not sit [in session] on the thirtieth day, nor would they await [the arrival] of witnesses. If witnesses came, they would know that they are false witnesses, or that clouds appeared to them in a form resembling the moon, but it was not the real moon.