(8) Remember the Sabbath day, to keep it holy.
(א) מִצְוַת עֲשֵׂה מִן הַתּוֹרָה לְקַדֵּשׁ אֶת יוֹם הַשַּׁבָּת בִּדְבָרִים שֶׁנֶּאֱמַר (שמות כ-ח) "זָכוֹר אֶת יוֹם הַשַּׁבָּת לְקַדְּשׁוֹ". כְּלוֹמַר זָכְרֵהוּ זְכִירַת שֶׁבַח וְקִדּוּשׁ. וְצָרִיךְ לְזָכְרֵהוּ בִּכְנִיסָתוֹ וּבִיצִיאָתוֹ. בִּכְנִיסָתוֹ בְּקִדּוּשׁ הַיּוֹם וּבִיצִיאָתוֹ בְּהַבְדָּלָה:
(1) It is biblically mandated positive commandment to sanctify the Sabbath with speech, as it is written (Exodus 20, 7): "Remember the Sabbath day, to keep it holy." i.e. Remember through remberance of praise and through Kiddush. And it must be remembered when it begins and when it ends. When it begins - with Kiddush, and when it ends - with Havdala.
(ז) כֵּיצַד הוּא עוֹשֶׂה. לוֹקֵחַ כּוֹס שֶׁהוּא מַחֲזִיק רְבִיעִית אוֹ יֶתֶר וּמְדִיחוֹ מִבִּפְנִים וְשׁוֹטְפוֹ מִבַּחוּץ וּמְמַלְּאֵהוּ יַיִן וְאוֹחֲזוֹ בִּימִינוֹ וּמַגְבִּיהוֹ מִן הַקַּרְקַע טֶפַח אוֹ יֶתֶר וְלֹא יַסִּיעַ בִּשְׂמֹאל. וּמְבָרֵךְ עַל הַגֶּפֶן וְאַחַר כָּךְ מְקַדֵּשׁ. וּמִנְהָג פָּשׁוּט בְּכָל יִשְׂרָאֵל לִקְרוֹת בַּתְּחִלָּה פָּרָשַׁת (בראשית ב-א) "וַיְכֻלּוּ" וְאַחַר כָּךְ מְבָרֵךְ עַל הַיַּיִן וְאַחַר כָּךְ מְקַדֵּשׁ וְשׁוֹתֶה מְלֹא לֻגְמָיו וּמַשְׁקֶה לְכָל בְּנֵי חֲבוּרָה וְאַחַר כָּךְ נוֹטֵל יָדָיו וּמְבָרֵךְ הַמּוֹצִיא וְאוֹכֵל:
What is the procedure he should follow: He should take a cup that contains a revi'it or more, wash it thoroughly inside, and rinse its outside. He should fill it with wine, hold it in his right hand, lifting it above the ground more than a handbreadth, without supporting it with his left hand. One recites the blessing [borey pri] hagefen and then the kiddush. It is, however, common custom among the Jewish people first to recite the passage Vayechulu, then the blessing [borey pri] hagefen and then the kiddush. One should drink [at least] a cheekful of wine and give all those joining in the meal to drink. Afterwards, one washes one's hands, recites the blessing hamotzi, and [begins] eating.
R. Zera said in the name of R. Abbahu (another version: it was taught in a Baraita): Ten things are said with reference to the cup used for the Grace after meals : It requires washing and rinsing, undiluted [wine] and must be full, crowning and covering ; he takes it with both hands and places it in the right hand, raises it a handbreadth from the floor and gazes at it.
(יג) צָרִיךְ לִשְׁתּוֹת מִכּוֹס שֶׁל קִדּוּשׁ כִּמְלֹא לֻגְמָיו, דְּהַיְנוּ כָּל שֶׁיְּסַלְּקֶנּוּ לְצַד אֶחָד בְּפִיו וְיֵרָאֶה מְלֹא לֻגְמָיו, וְהוּא רֻבּוֹ שֶׁל רְבִיעִית.
One needs to drink from the Kiddush Cup a cheek full, so that if we remove [all of the wine] to one side of his mouth, you will see that the cheek is full, and that is the majority of a revi'it.
(טו) אף ע"פ שאין ברכת המזון צריכה יין אם בירך על היין כמנהג שאמרנו צריך שידיח כוס של ברכה מבפנים ולשטוף אותו מבחוץ וימלאנו יין חי וכיון שהגיע לברכת הארץ נותן לתוכו מעט מים כדי שיהא ערב לשתיה ואין משיחין על כוס של ברכת המזון אלא הכל שותקים עד שתכלה ברכת המזון וברכת היין וישתו.
Although grace does not require wine, should one recite grace over wine according to the custom we have mentioned, [several conditions must be met:] One should wash out the cup over which the blessing is recited on the inside and rinse its outside. It should be filled with undiluted wine. When one reaches the blessing for Eretz Yisrael, one should add a small amount of water so that it will be pleasant to drink. Conversation should not be made over the cup over which grace is recited. Rather, everyone should remain silent until grace and the blessing of the wine is concluded, and then they should drink.