The Shulchan Aruch · Orach Chayim
אורח חיים תר״כOrach Chayim 620
Siman 620 of 697 in Orach Chayim — 1 se'if
הלכות יום הכיפוריםLaws of Yom Kippur· siman 620
Se’if 1א׳
טוֹב לְקַצֵּר בְּפִיּוּטִים וּבִסְלִיחוֹת שַׁחֲרִית, כְּדֵי לְמַהֵר בְּעִנְיָן שֶׁיִּתְפַּלֵּל מוּסָף קֹדֶם שֶׁבַע שָׁעוֹת.
The beautiful custom to shorten the Morning Prayers and in it is 1 paragraph It is good to shorten the liturgical hymns and penitential prayers of the Morning in order to hurry in the matter to pray Musaf before the 7th hour (of the day).
Shulchan Aruch, Orach Chayim — Torat Emet 363 edition, via Sefaria — public domain
English: Sefaria Community Translation — CC0