Jesus taught the disciples a lesson from what happened to a fig tree.

Matthew 21:18-22

18 Early the next morning, when we were returning to the city, Jesus was hungry. 19 He saw a fig tree near the road. So he went over to it to pick some figs to eat. But when he got close, he saw that there were no figs on the tree. There were only leaves on it. So to illustrate how God would punish the nation of Israel, he said to the fig tree, “May you never again produce figs!” As a result, the fig tree withered that night. 20 The next day when we disciples saw what had happened to the tree, we marveled, and we said to Jesus, “◄It is astonishing that the fig tree withered so quickly!/How is it that the fig tree dried up so quickly?►” [RHQ] 21 Jesus said to us, “Think about this: If you believe that God has power to do what you ask him to and you do not doubt that, you will be able to do things like what I have done to this fig tree. You will even be able to do marvelous deeds like saying to a nearby hill, ‘Uproot yourself and throw yourself into the sea’, and it will happen! 22 In addition to that, whenever you ask God for something when you pray to him, if you believe that he will give it to you, you will receive it from him.”