Parashas Ki Savo

Liyluy Nishmas Elchonon Tzvi ben R' Yisroel Menachem. In perek chaf zayin posuk zayin it says, " V'zavachta shlamim v'achalta sham v'samchta lifnei Hashem Elokecha" You shall slaughter peace offerings and eat there, and you shall rejoice before Hashem your God". The Sapurnu explains that "v'samachta lifnei Hashem Elokecha" is referring to rejoicing over the fact that Hashem entered a covenant, a bris, with Klal Yisroel by Har Grizim and Har Eival. It seems from the Sapurnu that we are obligated to rejoice over the occurences of both Har Grizim and Har Eivel. The Rosh Yeshivah ztl asks a seemingly obvious question. Its understandable to be happy over the fact that we were given the brachos at Har Grizim, however what warrants happiness by Har Eivel? That is where we were given all the klalos for doing things wrong, is that someting to be misameach about? The Rosh Yeshivah explains that
 we still should be b'simcha over the reception of the klalos because they are an extra shmira for us to hold us back from doing aveiros. Even for people who b'etzem know what is right and what is wrong and want to do the right thing have a difficult time. Without the klalos that difficult time would be multiplied, the fight would be that much greater. Therefore the Torah is telling us to be thankful to Hkbh for giving us the extra shmira to help us go in the right derech. Good Shabbos