Returning to Matthew and to 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), along with which He referred to the Temple authorities as robbers (for engaging in insurrection against the God of the Temple---an insurrection that will cause Israel’s God to bring upon Jerusalem and its Temple the same type of judgment that their 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 also happened to Jeremiah), Jesus 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 is reported to have caused a fig tree to wither for not producing fruit. This echoes Jeremiah’s repeated use of fig tree symbolism, and therefore becomes a clear allusion to the nation of Israel, which was failing in its task to be a light to the nations. This withering of the fig tree also functions as an allusion to the well-understood curses of the twenty-sixth chapter of Leviticus and the twenty-eighth chapter of Deuteronomy, which the Creator God (as Matthew writes from the post-Resurrection perspective of Jesus as the physical embodiment of Israel’s Creator 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). This is said to have caused the chief priests and the experts in the law to become “indignant” (21:15c).
Those that represented Israel before their 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 these words are heard, one must not lose sight of the fact 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 (Israel’s God returning to Zion and to the Temple), where the legitimacy of His presence there is challenged by the Temple authorities. This fact shall not be allowed to casually pass. This makes the point that it is the Temple mount that Jesus has in view when He speaks about the mountain being cast into the sea. It must be understood that it is the Temple that is central to Matthew’s narrative (along with Mark and Luke), and one must not lose sight of that fact while working towards an appropriate understanding of Jesus’ statement about the day and the hour that no one knows.