Ahavah Rabbah and Ahavat Olam
Overview
Both Ahavah Rabbah and Ahavat Olam are mentioned already in the Bavli where there is a disagreement between רב יהודה אמר שמואל and רבנן about whether one says Ahavah Rabbah or Ahavat Olam. But, it is unclear what the disagreement is about: both Shacharit and Arvit or just Shacharit and only the first two words of the berakhah or the whole berakhah.
Although it is possible that רב יהודה אמר שמואל held that one says Ahavah Rabbah even in Arvit, all the Geonim and Rishonim said Ahavat Olam. However, in Shacharit some said Ahavat Olam and some said Ahavah Rabbah. In סורא and then in אשכנז they were פוסק like רב יהודה אמר שמואל and said Ahavah Rabbah. In פומבדיתא and then in ספרד they were פוסק like רבנן and said Ahavat Olam.
Introduction
The second Berakha of the berakhot before Keriat Shema in Arvit is "אהבת עולם בית ישראל" and in Shacharit is "אהבה רבה אהבתנו". The content of the two berakhot seems to be very similar. Why do we have two berakhot and don't say the same one for Shacharit and Arvit?
Tannaim and Amoraim
The berakhot of Ahavah Rabbah and Ahavat Olam are found already in the Bavli (Berakhot 11b):
וְאִידָךְ מַאי הִיא? אֲמַר רַב יְהוּדָה אֲמַר שְׁמוּאֵל: ״אַהֲבָה רַבָּה״. וְכֵן אוֹרֵי לֵיהּ רִבִּי אֶלְעָזָר לר׳לְרִבִּי פְּדָת בְּרֵיהּ: ״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.
It is unclear if the gemara is talking about the berakhah one says in Shacharit or both in Arvit and Shacharit. It could be that everyone agreed that in Arvit one says "אהבת עולם" and the only disagreement was if in Shacharit one also says "אהבת עולם" or one says "אהבה רבה". Or, the disagreement was whether in both Arvit and Shacharit one says Ahavat Olam or in both Ahavah Rabbah.1
In addition, we don't know if the disagreement is about just the first two words or the whole berakha. The הגהות מיימוניות (and the ב"ח) says that the disagreement in the Bavli is just what the first two words are "אהבה רבה" or "אהבת עולם" and they agree about the rest of the berakha. But, it is possible that the disagreement is about the whole berakha. רב יהודה אמר שמואל and רבי אלעזר would say the berakha of "אהבה רבה אהבתנו ה' וכו'" and חכמים said one should say the berakha "אהבת עולם בית ישראל וכו'".
Geonim
All the Geonim agree that in Arvit one says אהבת עולם like רבנן2 but they disagree who one is פוסק like in Shacharit.
- פומבדיתא - In פומבדיתא they were פוסק like רבנן since they were the majority and said Ahavat Olam in Shacharit. However, it is unclear what they thought רבנן held, "אהבת עולם בית ישראל" or "אהבת עולם אהבתנו". It could be that in פומבדיתא they said "אהבת עולם בית ישראל" also in Shacharit or they said like Rasag has in his siddur "אהבת עולם אהבתנו"3.
- סורא - In Sura they were פוסק like ר' יהודה אמר שמואל in Shacharit and said Ahavah Rabbah. ר' שר שלום and ר' כהן צדק say that they are נוהג like that to be "יוצא ידי שניהם", in Arvit they hold like רבנן and say Ahavat Olam4 and in Shacharit they hold like ר' יהודה אמר שמואל and say אהבה רבה.
Rishonim and Acharonim
During the Rishonim time through the Acharonim time everyone said in Arvit "אהבת עולם בית" and in Shacharit the נוסח of "...אהבתנו ה' א-להינו...". The only disagreement was what the first two words were "אהבה רבה אהבתנו" or "אהבת עולם אהבתנו".
- ספרד - In ספרד they went כמנהג פומבדיתא and said "אהבת עולם אהבתנו".
- אשכנז - In אשכנז they went כמנהג סורא and said "אהבה רבה אהבתנו".
- מנהג פשרה בין אשכנז וספרד - The מנהיג says that one can do a פשרה and say "אהבת עולם רבה אהבתנו". The שערי תשובה says that the אר"י would say "אהבת עולם אהבתנו" on chol and "אהבה רבה אהבתנו" on Shabbat.