In many Bible translations the layout of this passage seems to imply a separation between the sixth and seventh verse. But these verses belong together, which helps to clarify the passage. Zechariah speaks here about the great work God is going to do among His people Israel. It is the same prophetic message we find in Ezekiel 34 and Jeremiah 33, just to mention some clear examples. God Himself will purify His chosen people. What a precious future for the sorely tried people of Israel, and how badly it is needed! For Israel still cannot fulfill its calling for the end-time, although we see many signs of the Spirit of God working in Israel.
It is very understandable that Zechariah speaks about the prophet and the spirit of impurity in the same sentence (:2). For the end-time will be characterized by fake piousness and false prophecies, while those who trust in the Lord will receive only a little help – just compare what is written in Matthew 7:22 and Daniel 11:33,34. But when God Himself will start to act, the prophets will fall silent and will deny they have spoken.
But how very different the Messiah will be. He will come and His feet will stand on the Mount of Olives (Zechariah 14:4), and then they will ask Him, ‘What are these wounds on Your body?’ And Jesus will answer, ‘The wounds I was given at the house of My friends.’ Then they will admit they have pierced the Shepherd, and they will mourn for Him as one mourns for an only child (Zechariah 12:10). On that day a fountain will be opened to the house of David and the inhabitants of Jerusalem, to cleanse them from sin and impurity (:1). Together with that Israel we say, ‘Come Lord, come!’