Mishnayos Rosh Hashanah Perek 1 Mishnah 9

With regard to one who saw the new moon but is unable to go to Jerusalem by foot because he is sick or has difficulty walking, others may bring him on a donkey or even in a bed, even on Shabbat if necessary. And if the witnesses are concerned that bandits may be lying in wait for them along the road, they may take clubs or other weapons in their hands, even on Shabbat. And if it was a long journey to Jerusalem, they may take sustenance with them, although it is ordinarily prohibited to carry on Shabbat, since for a distance of a walk of a night and a day, the witnesses may desecrate Shabbat and go out to give testimony to determine the start of the month. This is as it is stated: “These are the Festivals of the Lord, sacred gatherings, which you shall declare in their seasons” (Leviticus 23:4). This teaches that, in all cases, the Festivals must be fixed at their proper times, even if it entails the transgression of Torah prohibitions.

מִי שֶׁרָאָה אֶת הַחֹדֶשׁ וְאֵינוֹ יָכוֹל לְהַלֵּךְ, מוֹלִיכִין אוֹתוֹ עַל הַחֲמוֹר, אֲפִלּוּ בְמִטָּה. וְאִם צוֹדֶה לָהֶם, לוֹקְחִין בְּיָדָם מַקְּלוֹת. וְאִם הָיְתָה דֶרֶךְ רְחוֹקָה, לוֹקְחִין בְּיָדָם מְזוֹנוֹת, שֶׁעַל מַהֲלַךְ לַיְלָה וָיוֹם מְחַלְּלִין אֶת הַשַּׁבָּת וְיוֹצְאִין לְעֵדוּת הַחֹדֶשׁ, שֶׁנֶּאֱמַר (ויקרא כג), אֵלֶּה מוֹעֲדֵי ה' אֲשֶׁר תִּקְרְאוּ אוֹתָם בְּמוֹעֲדָם: