Heavy Lifting (Part 1 of ?)

During his talk last week, Jim Wallis mentioned "faith that could move a mountain" as a motivating force for social movements like abolition, women's suffrage, and civil rights. He was quoting Jesus as recorded in the Gospels, Matthew 21:21,22:

²¹Jesus replied, “I tell you the truth, if you have faith and do not doubt, not only can you do what was done to the fig tree, but also you can say to this mountain, ‘Go, throw yourself into the sea,’ and it will be done. ²²If you believe, you will receive whatever you ask for in prayer.”

Metaphorically, this is a powerful image of active faith but I've always struggled with the picture. Would Everest suddenly be flung to the sea? Would Shasta hover all the way to the Pacific? It never dawned on me to ask what mountain was Jesus talking about until recently when it was brought to my attention. What if there was one in particular he had in mind? Where did Jesus say this? Did he say it more than once? If there is a particular mountain, does it add to the picture of faith that Jesus is painting? Let's wrestle with this.