The eighth month of 520 b.c. began on October 27. Unlike the other dates given in Haggai and Zechariah, this one does not give the specific day of the month. While in Ezr 5:1 and 6:14, Zechariah is identified simply as a “descendant of Iddo,” here and in v. 7 he is identified both by his father's and grandfather's names. Other OT authors followed the common custom of mentioning only the grandfather. (For other explanations, cf. Meyers and Meyers, 92.)
Zechariah begins by reminding the Judahites that Yahweh had become very angry (qāṩap̱) with their forefathers (v. 2). This anger is most often associated with God's covenant name (Yahweh) and reflects his revulsion at rebellion among his creatures to whom he had bound himself in covenant. But Zechariah's point is that Yahweh's wrath, illustrated so unforgettably in the destruction of Jerusalem and the Babylonian exile, was directed toward their forefathers. For his generation, there was still time to avert further disaster by returning to God (v. 3). The repetition of the word return (šûḇ) in this introduction reveals the burden of the opening message. It was used often by the prophets to call the nation to repentance (Jer 3:12; Joel 2:12). Zechariah renews that message and assures his hearers that if they would only return to God, the covenant would once again be in effect (“I will return to you,” v. 3).
The expression “then they repented and said” (v. 6b) probably introduces a liturgical confession used in the postexilic cultic worship (Albert Petitjean, quoted and discussed in Baldwin, 92).