Many Jewish prayers are composed of 22 lines in aleph-to-tav acrostic sequence (e.g., Ashrei, Aishet Chayil), but Shabbat musaf features one in reverse: "Tikanta Shabbat ratzita qarbnoteiha, tzivita perusheiha 'im sidurei n'sacheiha...":

תִּכַּנְתָּ שַׁבָּת רָצִיתָ קָרְבְּנוֹתֶיהָ. צִוִּיתָ פֵּרוּשֶׁיהָ עִם סִדּוּרֵי נְסָכֶיהָ. מְעַנְּגֶיהָ לְעוֹלָם כָּבוֹד יִנְחָלוּ. טוֹעֲמֶיהָ חַיִּים זָכוּ. וְגַם הָאוֹהֲבִים דְּבָרֶיהָ גְּדֻלָּה בָחָרוּ. אָז מִסִּינַי נִצְטַוּוּ עָלֶיהָ. וַתְּצַוֵּנוּ יְיָ אֱלהֵינוּ לְהַקְרִיב בָּהּ קָרְבַּן מוּסַף שַׁבָּת כָּרָאוּי.
יְהִי רָצון מִלְּפָנֶיךָ יְיָ אֱלֹהֵינוּ וֵאלֹהֵי אֲבוֹתֵינוּ. שֶׁתַּעֲלֵנוּ בְשִׂמְחָה לְאַרְצֵנוּ וְתִטָּעֵנוּ בִּגְבוּלֵנוּ

"You established the Sabbath; found favor in its offerings; instructed regarding its commentaries along with the order of its showbreads. Those who delight in it will inherit eternal honor, those who savor it will merit life and also those who love the speech that befits it have chosen greatness. Then from Sinai they were instructed about it, when You commanded us, Hashem, our G-d, to offer on it the Sabbath musaf offering properly. May it be Your will, Hashem, our G-d and G-d of our forefathers, that You bring us up in gladness to our Land and plant us within our boundaries...."

Reverse acrostics are quite rare in our liturgy. Another place we see a reverse acrostic is in the Tefillat Tal (Prayer for Dew) on Pesach. This alphabetic reversal evokes our longing for the return to a state of perfection, the World to Come, of which our Shabbat is only a shadow.