Returning to Matthew, we learn that the day after Jesus’ triumphal entry into Jerusalem, which took Him to the Temple to pronounce a symbolic judgment against it in the mode of Jeremiah (and for the same reasons), and in which He referred to the Temple authorities as robbers (for engaging in insurrection against the God of the Temple---an insurrection that will cause God to bring upon Jerusalem and its Temple the same type of judgment that God brought upon it by way of Babylon, which are the thoughts that Jesus’ words and actions would have stirred, therefore setting him at odds with the Temple authorities and the people, as happened to Jeremiah), He returns to Jerusalem and to the Temple, having spent the night in the nearby village of Bethany (the home of Mary, Martha, and Lazarus).
On his way back to Jerusalem, Jesus causes a fig tree to wither for not producing fruit (echoing Jeremiah’s repeated use of fig tree symbolism, and therefore a clear allusion to the nation of Israel, which is failing in its task to be a light to the nations, and which also functions as an allusion to the curses of Leviticus 26 and Deuteronomy 28, which God---Matthew writes from the post-Resurrection perspective of Jesus as God---promised to bring upon His unfaithful people). This causing of the fig tree to wither, for Matthew, appears to stem from the reaction of “the chief priests and the experts in the law” (Temple authorities) when they “saw the wonderful things he did” (21:15a). Matthew alone (to the exclusion of Mark and Luke) reports that following Jesus’ talk of the Temple as den of robbers, “The blind and the lame came to Him in the Temple courts, and He healed them” (21:14). In addition, there were “children crying out in the Temple courts, ‘Hosanna to the Son of David’” (21:15b), which caused the chief priests and the experts in the law to become “indignant” (21:15c).
Those that represented Israel before God were unable to celebrate Jesus’ entry in the way of Solomon as pronounced by Zechariah, they refused to repent when one who had been attempting to be a Jeremiah (and more than a Jeremiah) to the people for three years called them to account, and they refused to rejoice in what was a rather obvious coming of their Messiah (in the mold of Isaiah 61) and His healing of the blind and the lame in the Temple courts. Little wonder then, that Jesus spoke to and about the fig tree in such a way. Matthew writes that “When the disciples saw it they were amazed” (21:20a), and wondered at what they had seen. To their amazed inquiry, Jesus replied “I tell you the truth, if you have faith and do not doubt, not only will you do what was done to the fig tree, but even if you say to this mountain, ‘Be lifted up and thrown into the sea,’ it will happen. And whatever you ask in prayer, if you believe, you will receive” (21:21-22).
As we hear these words, we cannot forget that Jesus is on His way into Jerusalem. Matthew will move immediately to add “Now after Jesus entered the Temple courts, the chief priests and elders of the people came up to Him as He was teaching and said, ‘By what authority are you doing these things, and who gave you this authority?’” (21:23). So the story of the fig tree and the words about the mountain are bracketed by Jesus being in the Temple, where the legitimacy of His presence is challenged by the Temple authorities. We cannot allow ourselves to casually pass by this fact. This informs us that it is the Temple mount that Jesus has in view when He speaks about the mountain being cast into the sea. We simply must understand that it is the Temple that is central to Matthew’s narrative (along with Mark and Luke).
For the sake of rounding out the Biblical picture, let us note what Mark presents in association with the fig tree and the mountain. Mark reports Jesus as saying “Whenever you stand praying, if you have anything against anyone, forgiven him, so that you Father in heaven will also forgive your sins” (11:25). Luke omits any mention of the fig tree our mountain, moving directly to Jesus return to the Temple courts and the challenge to Jesus’ authority. Though we will not spill a great deal of ink with conjecture on why Matthew and Mark include the story of the withered fig tree whereas Luke does not, we could surmise that the appearances of the fig tree in the Matthean and Markan narratives, with both (Matthew most likely relying on Mark) connecting the withered fig tree with the mountain to be removed, could possibly have some bearing on the conclusions to be drawn.