Berakhot 11b
ברכות י״א ב — ד"ה וְאִידָּךְ מַאי הִיא
Berakhot 11b:8
The blessing recited before Shema is "An abounding love" (ahava rabba), which praises God's love for Israel and includes the essential components of a blessing over Torah; therefore, one who has already recited Shema is exempt from reciting a separate blessing over Torah, as the ahava rabba blessing fulfills that obligation.
וְאִידָּךְ מַאי הִיא? אָמַר רַב יְהוּדָה אָמַר שְׁמוּאֵל: ״אַהֲבָה רַבָּה״. וְכֵן אוֹרִי לֵיהּ רַבִּי אֶלְעָזָר לְרַבִּי פְּדָת בְּרֵיהּ, ״אַהֲבָה רַבָּה״. תַּנְיָא נָמֵי הָכִי: אֵין אוֹמְרִים ״אַהֲבַת עוֹלָם״, אֶלָּא ״אַהֲבָה רַבָּה״. וְרַבָּנַן אָמְרִי אַהֲבַת עוֹלָם, וְכֵן הוּא אוֹמֵר: ״וְאַהֲבַת עוֹלָם אֲהַבְתִּיךְ עַל כֵּן מְשַׁכְתִּיךְ חָסֶד״. אָמַר רַב יְהוּדָה אָמַר שְׁמוּאֵל: הִשְׁכִּים לִשְׁנוֹת, עַד שֶׁלֹּא קָרָא קְרִיאַת שְׁמַע — צָרִיךְ לְבָרֵךְ. מִשֶּׁקָּרָא קְרִיאַת שְׁמַע — אֵינוֹ צָרִיךְ לְבָרֵךְ, שֶׁכְּבָר נִפְטַר בְּ״אַהֲבָה רַבָּה״.
The Gemara asks: And what is the formula of the other blessing recited before Shema? Rav Yehuda said in the name of Shmuel: An abounding love [ahava rabba]. And Rabbi Elazar instructed his son, Rabbi Pedat, to also say: An abounding love. That was also taught in a baraita: One does not recite: An eternal love [ahavat olam]; rather, one recites: An abounding love. And the Rabbis say that one recites: An eternal love, and so it says: “And an eternal love I have loved you, therefore I have drawn you with kindness” (Jeremiah 31:3). The blessing: An abounding love, is about God’s love for us and includes praise for His giving us the Torah. Therefore, Rav Yehuda said that Shmuel said: One who arose to study, until he recites Shema he must recite a special blessing over the Torah. If he already recited Shema he need not recite that blessing, as he has exempted himself by reciting the blessing of: An abounding love, which includes the components of the blessing over the Torah.