Where is the word "Va'achaltem Sham Lifnei Hashem Elokeichem" referring to and what is it that must be eaten there?
Rashi (in Zevachim, 112b): It refers to eating Kodshim Kalim (Shelamim and Todos) and Ma'aser Sheini within the walls of Yerushalayim. 1
Rashi (in Zevachim, 112b): Which is equivalent to the Machaneh Yisrael in the desert.
What are the connotations of "Lifnei Hashem Elokeichem"?
Sifri: It means that each one should be eaten in its alloted area - some (Kodshim Kalim) in Yerushalayim and some (Kodshei Kodshim) in the Azarah. 1
See Torah Temimah, note 30.
What is the significance of the Simchah here?
Seforno: When you come before Hashem it is befitting that you should be happy, 1 as the Pasuk writes in Tehilim, 10:2 "Ivdu es Hashem be'Simchah".
Yerushalmi Chagigah, 1:2: It refers to the Mitzvah of eating Shelamim - be'Simchah - which we learn via a Gezeirah Shavah "u'Semachtem" "Vesamachta" from Har Gerizim and Har Eival, in Ki Savo, 27:7. 2
What are the implications of "asher Berach'cha Hashem Elokecha"?