By Zechariah 7, the people had been captive in Babylon for roughly 68 years, just shy of the requisite 70 years. Because they had been forced out of their Land, they wept and fasted each year to remember the event. The trouble was that though they were remembering the event with weeping and fasting, God had not necessarily told them to do that. Beyond this, had they lived in obedience to Him, they would not have been removed from the Land forcibly and there would have been no need to fast and weep for their loss. They brought it on themselves by their refusal to live as God wanted them to live. But instead of recognizing this fact, the people sent a couple of representatives to "inquire" of the priests and ultimately, of Zechariah the prophet regarding their weeping and fasting over that event.