13:1 For the last time in the book of Zechariah God makes a promise regarding the house of David. The promise also includes the inhabitants of Jerusalem. This is the eighth of seventeen promises in chapters 12–14 that begin with the phrase, on that day. A fountain will be opened in Jerusalem. Ezekiel 47:1–12, Joel 3:18, and Zechariah 14:8 describe an eschatological water source that will flow out of the temple and water the land. This fountain in 13:1 has a ritual purpose to cleanse [the house of David and the inhabitants of Jerusalem] from sin and impurity. Water purifies people and objects from uncleanness that results from contact with the dead, according to the torah in Numbers 19 and 31:23. The water of cleansing prepares the Levites for service by making them ceremonially clean (Num.…