Berachos2: 2
אֵלּוּ הֵן בֵּין הַפְּרָקִים: בֵּין בְּרָכָה רִאשׁוֹנָה לִשְׁנִיָּה, בֵּין שְׁנִיָּה לִ,,שְׁמַע“, וּבֵין ,,שְׁמַע“ לִ,,וְהָיָה אִם־שָׁמֹעַ“, בֵּין ,,וְהָיָה אִם־שָׁמֹעַ“ לְ,,וַיֹּאמֶר“, בֵּין ,,וַיֹּאמֶר“ לֶ,,אֱמֶת וְיַצִּיב“. רַבִּי יְהוּדָה אוֹמֵר: בֵּין ,,וַיֹּאמֶר“ לֶ,,אֱמֶת וְיַצִּיב“ לֹא יַפְסִיק. אָמַר רַבִּי יְהוֹשֻׁעַ בֶּן קָרְחָה: לָמָּה קָדְמָה ,,שְׁמַע“ לִ,,וְהָיָה אִם־שָׁמֹעַ“? אֶלָּא כְּדֵי שֶׁיְּקַבֵּל עָלָיו עֹל מַלְכוּת שָׁמַיִם תְּחִלָּה, וְאַחַר כָּךְ יְקַבֵּל עָלָיו עֹל מִצְוֹת. ,,וְהָיָה אִם־שָׁמֹעַ“ לְ,,וַיֹּאמֶר“? שֶׁ,,וְהָיָה אִם־שָׁמֹעַ“ נוֹהֵג בַּיּוֹם וּבַלַּיְלָה; ,,וַיֹּאמֶר“ אֵינוֹ נוֹהֵג אֶלָּא בַיּוֹם
These are between the sections [of the Shema and its blessings]: Between the first blessing and the second [blessing]; between the second [blessing] and [the passage of] ‘‘Shema’’ (Deuteronomy 6:4-9); and between ‘‘Shema’’ and [the passage of] ‘‘Vehayah im shamoa’’ (Deuteronomy 11:13-21); between ‘‘Vehayah im shamoa’’ and [the passage of] ‘‘Vayomer’’ (Numbers 15:37-41); between ‘‘Vayomer’’ and [the blessing of] ‘‘Emes Veyatziv.’’ R’ Yehudah says: Between ‘‘Vayomer’’ and ‘‘Emes Veyatziv’’ one may not in-terrupt. R’ Yehoshua ben Korchah said: Why does [the passage of] ‘‘Shema’’ precede [the passage of] ‘‘Vehayah im shamoa’’? Only so one will first accept upon himself the yoke of Heaven’s sovereignty, and afterward accept upon himself the yoke of [the] command-ments. And [why does] ‘‘Vehayah im shamoa’’ [precede the passage of] ‘‘Vayomer’’? Be-cause ‘‘Vehayah im shamoa’’ applies by day and by night, [whereas] ‘‘Vayomer’’ applies only by day.