The metaphorical meaning of mountains as symbols of God’s promises and blessings is based upon the words of Jacob in Genesis 49:26 where he said, as he blessed Joseph:
The blessings of thy father have prevailed above the blessings of my progenitors unto the utmost bound of the everlasting hills.
Mountains, rivers, valleys, hills, coasts, wilderness, desert, are all part of the land that God promised to give Abraham, and to Isaac, and to Jacob. Belief was required for the Israelites to enter the land of promise. [Heb. 3:19] Jacob discovered that the things that must be believed, promises of spiritual blessings, are represented by mountains and hills.
The promises he received were lofty and spiritual, and so were high like high mountains, and also durable, or eternal, so he compared them to the “everlasting hills.”
The table below lists many prophecies that refer to mountains, with brief explanatory notes.