It wasn’t the season for figs, yet he thought the tree might have figs anyway because generally figs bloom before the leaves (v. 13).  He miraculously withered it for two reasons:

1. To show the apostles that they could perform miracles if they pray in faith (vs. 22-24; cf. Matt. 17:20) and with an attitude of forgiveness (v. 25)
2. To show the symbolic parallel between the fig tree that falsely advertised through its leaves that it had fruit and the majority of the Jews who proclaimed themselves followers of God yet inside were spiritually bankrupt (cf. Hos. 9:10; Joel 1:7; Mic. 7:1-6; Mark 11:1-10, 15-18; Matt. 21-24; Rom. 2:17-24; 11:7ff).