1)
What is "He'ach"?
1.
Rashi, Targum Yonasan: It is an expression of Simchah.
2)
What is "Bamos Olam"?
1.
Rashi: It is Eretz Yisrael, which is the height and beauty of the world. Radak ? it says "Haysah" regarding the land, which includes the Bamos.
