בַּיּ֣וֹם הַה֗וּא יִֽהְיֶה֙ מָק֣וֹר נִפְתָּ֔ח לְבֵ֥ית דָּוִ֖יד וּלְיֹשְׁבֵ֣י יְרֽוּשָׁלִָ֑ם לְחַטַּ֖את וּלְנִדָּֽה׃
In that day there shall be a fountain opened To the house of David and to the inhabitants of Jerusalem, For purification and for sprinkling.
Read kabbalistic (mystical) interpretation of Zechariah 13:1: and classical mystical sources.