Mishnayos Brachos Perek 2 Mishnah 2

As for what constitutes a paragraph, these are the breaks between the paragraphs: Between the first blessing and the second, between the second and Shema, between Shema and the second paragraph: If you indeed heed My commandments [VeHaya im Shamoa], between VeHaya im Shamoa and the third paragraph: And the Lord spoke [VaYomer] and between VaYomer and True and Firm [emet veyatziv], the blessing that follows Shema. The Rabbis held that each blessing and each paragraph of Shema constitutes its own entity, and treat interruptions between them as between the paragraphs. Rabbi Yehuda, however, says: Between VaYomer and emet veyatziv, which begins the blessing that follows Shema, one may not interrupt at all. According to Rabbi Yehuda, these must be recited consecutively. Since the paragraphs of Shema are not adjacent to one another in the Torah, and they are not recited in the order in which they appear, the mishna explains their placement. Rabbi Yehoshua ben Korḥa said: Why, in the mitzva of the recitation of Shema, did the portion of Shema precede that of VeHaya im Shamoa? This is so that one will first accept upon himself the yoke of the kingdom of Heaven, the awareness of God and God’s unity, and only then accept upon himself the yoke of the mitzvot, which appears in the paragraph of VeHaya im Shamoa. Why did VeHaya im Shamoa precede VaYomer? Because the paragraph of VeHaya im Shamoa is practiced both by day and by night, while VaYomer, which discusses the mitzva of ritual fringes, is only practiced during the day.

אֵלּוּ הֵן בֵּין הַפְּרָקִים, בֵּין בְּרָכָה רִאשׁוֹנָה לִשְׁנִיָּה, בֵּין שְׁנִיָּה לִשְׁמַע, וּבֵין שְׁמַע לִוְהָיָה אִם שָׁמֹעַ, בֵּין וְהָיָה אִם שָׁמֹעַ לְוַיֹּאמֶר, בֵּין וַיֹּאמֶר לֶאֱמֶת וְיַצִּיב. רַבִּי יְהוּדָה אוֹמֵר, בֵּין וַיֹּאמֶר לֶאֱמֶת וְיַצִּיב לֹא יַפְסִיק. אָמַר רַבִּי יְהוֹשֻׁעַ בֶּן קָרְחָה, לָמָּה קָדְמָה שְׁמַע לִוְהָיָה אִם שָׁמֹעַ, אֶלָּא כְדֵי שֶׁיְּקַבֵּל עָלָיו עֹל מַלְכוּת שָׁמַיִם תְּחִלָּה, וְאַחַר כָּךְ יְקַבֵּל עָלָיו עֹל מִצְוֹת. וְהָיָה אִם שָׁמֹעַ לְוַיֹּאמֶר, שֶׁוְהָיָה אִם שָׁמֹעַ נוֹהֵג בַּיּוֹם וּבַלַּיְלָה, וַיֹּאמֶר אֵינוֹ נוֹהֵג אֶלָּא בַּיּוֹם: