English Basic Explanation - Chapter 114
This chapter, the second paragraph which we recite as part of the Hallel service on holidays, speaks of the events that occurred to Bene Yisrael after the Exodus from Egypt. It describes the sea "fleeing," the Jordan River "retreating," and the mountains and hills "dancing" in the presence of God. According to the Radak, these images refer to the events of the splitting of the Sea of Reeds, the splitting of the Jordan River, and Matan Torah (the giving of the Torah at Mount Sinai). The Sea of Reeds (Yam Suf) split to allow Bene Yisrael to escape from the pursuing Egyptian army (Shemot, chapter 14), and the Jordan River split when Bene Yisrael entered the Land of Israel under the leadership of Yehoshua (Yehoshua, chapter 4). At Matan Torah, Mount Sinai as well as the surrounding hills trembled as the divine presence descended upon the mountain.
This Psalm declares (verse 2) that when Bene Yisrael earned their freedom from bondage and left Egypt, they became God's "sacred nation" ("Hayeta Yehuda Le'kodsho") and His "governed people" ("Yisrael Mamshelotav"). The event of the Exodus involved much more than simply an oppressed nation earning its freedom; it meant the transformation of Am Yisrael into God's special nation, with all the privileges and responsibilities that this entails. The miraculous events that followed – such as the splitting of the sea and the Jordan River, and the Revelation at Sinai – demonstrate the unique status as Am Yisrael, that their freedom from bondage was intended not merely for the sake of personal liberty, but rather to allow them to become the loyal subjects of the Almighty.