We have the custom to blow the shofar throughout the month of Elul as a preparation for Rosh HaShanah. The shofar comes to wake us up but also to gather us together in order that we can return to God together.
The Three Weeks between the 17th of Tamuz and the 9th of Av are a time of sadness and danger. Rav Kook shows that they are also a time during which we can rebuild the Temple if we learn the secret of Causeless Love.
The Mishnah teaches us that the tablets were broken on the 17th of Tamuz as a result of the building of the Golden Calf. Rav Kook explains that if we understand the essence of idolatry we can find a way to mend the broken tablets.