What is yom hashishi prayer?

The Yom HaShishi prayer refers to the paragraph beginning with the words "Yom HaShishi" (יוֹם הַשִּׁשִּׁי — "the sixth day") that is recited on Friday night as part of the Kiddush (sanctification over wine) before the Shabbat evening meal. It is not a standalone prayer but rather the opening of the Friday night Kiddush, formed by combining the last verse of the sixth day of Creation with the Shabbat verses from Genesis, followed by the blessing over wine.

Key Takeaways

Yom HaShishi is the opening word-phrase of the Friday night Kiddush, taken from Genesis 1:31.
The first letters of the opening four words — יוֹם הַשִּׁשִּׁי ויְכֻלּוּ הַשָּׁמַיִם — spell out יהוה (the Divine Name), which is considered deeply significant.
The core of the Kiddush is the paragraph of Vayechulu (Genesis 2:1–3), testifying that God rested on the seventh day.
Reciting Vayechulu on Friday night is considered an act of testimony (edut) that God created the world.
The Kiddush fulfills the Torah commandment to "remember the Sabbath day" (Zachor et yom haShabbat — Exodus 20:8).

Detailed Answer

What Is the Text?

The Friday night Kiddush opens with two verses drawn from the Torah:

יוֹם הַשִּׁשִּׁי וַיְכֻלּוּ הַשָּׁמַיִם וְהָאָרֶץ וְכׇל־צְבָאָם "The sixth day. And the heavens and earth were completed, and all their hosts." [Genesis 1:31–2:1]

This is followed by:

וַיְכַל אֱלֹהִים בַּיּוֹם הַשְּׁבִיעִי מְלַאכְתּוֹ... וַיְקַדֵּשׁ אֹתוֹ "And God completed on the seventh day His work... and He sanctified it." [Genesis 2:2–3]

The Hidden Divine Name

One of the most celebrated features of this opening is noted by Tosafot and other commentators: the first letters of the four opening words —

יוֹם הַשִּׁשִּׁי ויְכֻלּוּ הַשָּׁמַיִם

— spell יהוה (the Tetragrammaton, God's ineffable Name).

This is understood as hinting that the sanctity of Shabbat is bound up with the Divine Name itself, and it is one reason why the word Yom HaShishi (which ends the previous verse in Genesis) is included even though the Kiddush technically begins with Vayechulu.

Why Vayechulu Is Recited

The Talmud teaches that one who recites Vayechulu on Friday night is considered as if he became a partner with God in the work of Creation [Shabbat 119b]:

"כל המתפלל בערב שבת ואומר ויכולו — מעלה עליו הכתוב כאילו נעשה שותף להקדוש ברוך הוא במעשה בראשית" "Anyone who prays on Shabbat eve and says Vayechulu — Scripture accounts it as though he became a partner with the Holy One, blessed be He, in the act of Creation."

This is because reciting these verses constitutes testimony (edut) before the world that God is the Creator. Just as witnesses must stand in pairs, some authorities note that Vayechulu should ideally be recited with another person [Shabbat 119b; see Rashi ad loc.].

Connection to the Commandment of Kiddush

The broader obligation of Kiddush comes from the verse:

זָכוֹר אֶת יוֹם הַשַּׁבָּת לְקַדְּשׁוֹ "Remember the Sabbath day to sanctify it." [Exodus 20:8]

The Rabbis derived from the word zachor ("remember") that this remembrance must be expressed verbally, and specifically over a cup of wine [Pesachim 106a]. The Yom HaShishi / Vayechulu text serves as the verbal declaration of Shabbat's sanctity.

Connection to the Retrieved Sources

One of the retrieved sources is particularly relevant here:

Deuteronomy 11:13 — "וּלְעׇבְד֔וֹ בְּכׇל־לְבַבְכֶ֖ם" — "and to serve Him with all your heart" — is understood by the Sages as referring to prayer (avodah shebalev — service of the heart) [Taanit 2a]. The Kiddush, while a distinct ritual, partakes of this spirit of wholehearted service and proclamation before God.

Practical Halachic Notes

Yom HaShishi + Vayechulu is recited standing by many communities, in keeping with the idea of giving testimony (witnesses stand before a court).
It is recited both during Maariv (evening prayer) at synagogue and again at the home Kiddush over wine.
Women are obligated in Kiddush despite it being a time-bound positive commandment, because the verse links zachor ("remember") with shamor ("observe") [Berachot 20b].

For personal guidance on how to recite Kiddush in your specific community's custom (Ashkenaz, Sefard, Edot HaMizrach, etc.), consult your local rabbi or posek.