Hallel At The Seder

The Rishonim ask why there is no blessing made on the hallel that we say at the seder?  [They ask this question on the 4 cups and the mitzvah of sippur yitzias mitzraim as well, but this post will focus on hallel.]  The simple answer is that we do; our practice is wrong.  Some Rishonim indeed said a beracha on hallel at the seder.  The Ramban in essence maintains this way as well but he holds the blessing said on the hallel at the synagogue at the conclusion of maariv exempts saying a beracha on hallel at the seder; one who didn't say hallel previously indeed should say a beracha at the seder.  According to the Ramban, why do we do a double hallel; one at the synagogue and then again at the seder?  If you look carefully at the Ramban it seems the hallel is recited like any other hallel of a yom tov but the optimal time is to do the hallel at the time of the mitzvot; hence we do it ברבים in the synagogue and then repeat it at the seder for it is the optimal time of saying hallel.

Another approach is that which is indicated in the Chinuch (#21) and Rambam Sefer Hamitzvot (#157) that the hallel of seder night is merely an extension of sippur yitzias mitzraim.  In other words, we aren't saying hallel as a separate mitzvah of hallel, its part of the general mitzvah of sippur yitzias mitzraim.  Based upon this, there wouldn't be a beracha for its only part of the general mitvah of sippur yitzias mitraim and we don't say a beracha on part of a mitzvah.

The Ran cites in the name of Rav Hai Gaon and Rav Tzemach Gaon that there is no beracha for we don't say the hallel as the mitzvah of hallel rather as a shirah.  The other Rishonim cite Rav Tzemach explains there is no beracha on the hallel because we interrupt it in the middle with matzah, seudah etc, so how can the Ran lump the two together?  The Briskor Rav (Laws of Hallel) understands that the reason of Rav Tzemach isn't a separate reason, its merely a siman that the hallel of the seder is a different form of hallel; that of shirah.  This form of hallel of shirah doesn't have a beracha.  It is clear the Ramban doesn't understand that way for he attacks the reason of the interruption and proves even when a mitzvah is interrupted one may still recite a beracha.  Clearly, he understood Rav Tzemach is its own reason and not just a siman and hence attacks his reason.  The Ramban doesn't even mention Rai Gaon's reason, why not?  It makes sense that the Ramban wouldn't understand like the distinction of the Rav between two different forms of hallel for in his view in Sefer Hamitzvot shoresh 1, all hallel is is the hallel of simcha; even that recited on a holiday, so there is no room to say like Rav Hai Gaon.  (The Mordechai and Rokeach defend Rav Tzemach that he means that the Rabbis wouldn't enact a beracha initially on a mitzvah that will be interrupted.) 

However, if one reads other Rishonim carefully, you will see the Rishonim understand Rav Hai differently than the Briskor Rav.  It is clear from the Rabbenu Dovid, Mordechai, Ritvah Sukkah 38 that Rav Hai means not that his is a different form of hallel; a hallel of shira, but that we are merely saying pessukim of praise to Hashem and we happen to pick the pessukim of hallel but it si not a recitation of hallel.  In the words of the Ritvah, it is a zemer, a song of praise to Hahem, not hallel.  [Indeed, according to the Ramban as we just explained he holds there is a beracha on hallel of shirah so he can't learn Rav Hai this way and that is also the opinion of Rabbenu Tam cited by Rabbenu Yonah in Berachos 14 as the Rav himself brings; therefore the Rishonim can't say like the Rav's peshat in Rav Hai if that is their opinion as well.]  Based upon this, if we want to understand the Ran in this vein as well we must say that he puts Rav Hai together with Rav Tzemach not because they are saying the same reason, but merely because they share the same practicality; there is no beracha on hallel at the seder.  In the Or Zarua this is clearly the peshat for he opens by lumping the two together and then brings both reasons.  According to this approach, hallel of shirah may have a beracha but the hallel of the seder isn't hallel, merely pessukim of shirah and that is why there is no beracha. 

Some Rishonim (see Mordechai Pesachim in name of Ritzvah for example) say that one should say two berachos on hallel at the seder.  One beracha at the beginning לקרוא הלל and a second beracha at the end לגמור את ההלל.  That is because they are bothered by the interruption of the hallel, hence, they advise two berachos.  How can one say two berachos on one mitavah?  Unless they mean that in the answer they are retracting, its not one hallel with an interruption; its two forms of hallel, the first is the hallel of shirah and the second is that of regular hallel.  However, it doesn't sound like that, and then why would the text of the beracha change, if its a new hallel, it doesn't come to complete the old one, so why would we say לגמור את ההלל at the end?
(Largely based upon shiurim by Rabbi Ezra Shochet given in the past week's specifically shiur #5,6 on the Rebbe's Haggadah available on YouTube, see also Reshimos Shiurim Berachos 14 and Ma'adanay Moshe siman 22.)