TISH’A BEAB: The prophet Jeremiah, and the opportunity we missed.

In the days of King Joakim, HaShem spoke to the prophet Yirmiyahu and told him to go to Bet haMiqdash and transmit this message:
CAP 26: 1-6 “Thus says HaShem, … speak to all [those coming to the Temple from] the cities of Yehuda  … do not omit a word. Perhaps they will listen and repent of their evil ways. If they do that, [I will also] repent of the evil that I thought to do [with Bet haMiqdash and Yerushalayim] because of their wicked deeds. Warn them, that thus says HaShem: ‘If they do not obey and behave by the law which I have given them, and if they do not listen to the words of my servants the prophets, whom I have sent again and again, and they have disobeyed, then will I make this house what I did to Shiloh. ‘ “

Here the prophet shows what his mission really is. The prophecy that announced the destruction of the Bet haMiqdash, at this time, can still be avoided. HaShem sent the prophets to save His people from the consequences of their wrongdoing. It might happen to the Bet haMiqdash what happened to the Mishkan of Shilo, which was destroyed by the Philistines in the days of the prophet Samuel. But if the people repent and correct their behavior, destruction can still be avoided!
The question is: How did people react to these words? Did they listen to the warnings of Yirmiyahu and correct themselves?
The Priests, and false prophets, who were the leaders of the Temple wanted to execute Yirmiyahu. They saw that this new prophet threatened their authority and leadership, and began to lynch Yirmiyahu. How did they justify this? They accused Yirmiyahu of being the bearer of bad news. The false prophets announced that everything was fine. They presented Yirmiyahu as a heretic and demanded his execution. The hypocritical priests and the false prophets said: How can this man say that the Bet haMiqdash will be destroyed? Does he think that HaShem does not have the power to prevent the destruction of His Sanctuary?
But, as we have explained, the building Bet haMiqdash, its walls, enclosures, ceilings, etc. meant nothing if the people who dwell in the Sanctuary did not live their lives with integrity. People who acted viciously in their daily affairs, could not come to the Bet-haMiqdash expecting an instantaneous cleansing from the sins that they were still consciously practicing. The religious ritual, if it not accompanied by a good religious behavior, can become a form of cynicism and sacrilege.
Yirmiyahu’s strong words against this hypocritical attitude speak for themselves:
CAP 7: 3- 11 “Amend your ways and your wrongdoings, and I’ll let you go on living in this country. Do not trust the deceptive words [that the false prophets] repeated: ‘This is the temple of the Lord, the temple of the Lord, the temple of the Lord [which will never be destroyed]’…. but if you correct your behavior and your actions, if you practice justice with one another, if you do not oppress the stranger or the orphan and the widow, if you do not shed innocent blood in this place, if you do not follow other gods … then I’ll let you go living … in the land that I gave to your ancestors forever …. [But, so far] you … steal, you kill, you commit adultery, you swear falsely, you burn incense to the Baal, and you follow other gods … and then you come and appear before Me in this house that bears my name [=the Bet haMiqdash] and you say: “[Here] we’ll be safe ‘, and then you go on committing all these abominations! Do you believe that this house that bears My name is a refuge of thieves? “.
We, the Yehudim of that generation, missed the opportunity to do Teshuba, to absorb the prophet’s message and repent. And soon the city of Jerusalem and its Temple were destroyed.
Yirmiyahu words, unfortunately, were not heard in his generation. But they were written for future generations. For us. In these coming days, which are days of national mourning, our primary mission is to dedicate ourselves to introspection, remembering the mistakes of our ancestors to correct them and never repeat them again.

Halakhot of Tish’a beAb
Tomorrow begins the month of Ab, and for nine days some customs and rules of mourning apply. See here  some of the Halakhot regarding building, renovating, moving to a new home, buying or wearing something new during the nine days, etc