Psalms 114:1-4

When God brought the Israelites out of Egypt, He dwelt among them and ruled over them. The names Judah and Israel are in poetic parallelism here and refer to the same group, namely, the nation of Israel. Judah was its leading tribe.

The writer personified the Red Sea as seeing the Israelites coming and fleeing from them by parting its waters. Later when the Israelites entered the Promised Land, the Jordan River backed up as far as the town of Adam, farther north in the Jordan Valley, to let them cross. The mountains around Sinai quaked when God came down on Mt. Horeb to meet with His people.