In order to understand this chapter, we must rewind to the end of Zechariah 12. In the end times, after Jesus has returned, Zechariah predicts a time of mourning where Israel will finally realize their sin against The Messiah. Through their Godly sorrow comes repentance which leads to the washing away of sin and impurity (13:1).
Once and for all, idolatry will be cut off. Once and for all, those who spew false prophecies and lead the people astray will be destroyed. In fact, Zechariah speaks toward a time when public opinion will no longer tolerate the false prophets in their land. With the Holy Spirit powerfully present over the nation of Israel, His discernment will rule. In that time no one will even want to be identified as a prophet.
Instead, he will say, ‘I am not a prophet. I am a farmer—I have farmed the land all my life.’ 6 Then if someone asks him, ‘What are those wounds on your chest?’ he will answer, ‘I got them at a friend’s house.’ “
Zechariah 13:5-6 GNB
This does not mean that prophecy itself would cease but that those who speak falsely would be exposed. The reason we must look back at Zechariah 12 is to remember that all of this wisdom and discernment came from Jesus dwelling with His people. Mourning, repentance, and turning to Jesus led to a clarity that unified the people. Finally, they were able to turn from their idolatry and the deceit of false prophets.
It is important to realize that through the Holy Spirit this same discernment is available today!