1)
Why is this a new Dibur?
1.
Radak: The first Dibur was for Zerubavel and Yehoshua. This Dibur was for the nation.
2.
Malbim: Hashem aroused the light of Nevu'ah to sprout. This is a sign that if they will repent, Nevu'ah will return to them like initially, and the time of Tikun will come.
