zechariah 13:1 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. - Free Bible Online

      Zec 13:1-9. CLEANSING OF THE JEWS FROM SIN; ABOLITION OF IDOLATRY; THE SHEPHERD SMITTEN; THE PEOPLE OF THE LAND CUT OFF, EXCEPT A THIRD PART REFINED BY TRIALS.

      1. Connected with the close of the twelfth chapter. The mourning penitents are here comforted.
      fountain opened--It has been long opened, but then first it shall be so "to the house of David," &c. (representing all Israel) after their long and weary wanderings. Like Hagar in the wilderness they remain ignorant of the refreshment near them, until God "opens their eyes" (Ge 21:19) [MOORE]. It is not the fountain, but their eyes that need to be opened. It shall be a "fountain" ever flowing; not a laver needing constantly to be replenished with water, such as stood between the tabernacle and altar (Ex 30:18).
      for sin . . . uncleanness--that is, judicial guilt and moral impurity. Thus justification and sanctification are implied in this verse as both flowing from the blood of Christ, not from ceremonial sacrifices (1Co 1:30; Heb 9:13, 14; 1Jo 1:7; compare Eze 36:25). Sin in Hebrew is literally a missing the mark or way.

JFB.