When is 'that day' in Zechariah 13:1?
According to the context, 'that day' is when the Lord finally establishes His kingdom and Israel receives all promised fulfillment. At that time a fountain will be opened to the house of David and Jerusalem's inhabitants for sin and uncleanness, bringing cleansing, forgiveness, and entrance into the kingdom's glory.
Les teaches that Zechariah 13:1 is prophecy. He explains 'in that day' as the time when the Lord finally sets up His kingdom and Israel has all the promises fulfilled. The verse says a fountain will be opened to the house of David and to the inhabitants of Jerusalem for sin and uncleanness. Les says God will cleanse them, forgive them, and they will come into all the glory of the kingdom. But as yet, they are out there in their spiritual blindness. This connects to the sign of the blind man washing in Siloam, showing Israel's near-term rejection and falling away, yet long-term God will fulfill all these sign aspects of His dealing with Israel.
In that day there shall be a fountain opened to the house of David and to the inhabitants of Jerusalem for sin and for uncleanness.