condensed from Ein Ayah, Shabbat 2:47)


Gemara: [When the gates of the Beit Hamikdash opened after Shlomo invoked David’s merit], the whole nation and all of Israel knew that Hashem forgave him for that sin [of Batsheva].

Ein Ayah: The Nation of Israel is so elevated that it is fit to be an eternal nation. This elevation must be in a manner that even every individual has a respectable level. The nation’s impact should not be only by means of the nation as a whole but even by means of its individuals. This element is hinted at in the pasuk: "Hashem will count when the nations are written, this one was born there" (Tehillim 87:6).
Therefore, the one who merited being the cornerstone of theKingdom of Israel for all generations must have an influence of sanctity, full of ethics and justice forever, whether for the individual or the nation as a whole. This point was stressed at the time that the eternity of the nation was connected to the sanctity of the Torah. This found expression in the Holy of Holies [where the ark was kept] and showed the eternity of the Kingdom of the House of David. Therefore, it is important that at the time this became known, the people should know that the anointed king had been purified from his sin. It is not only that David’s repentance had a positive impact upon him in that his internal essence had been rectified and the bad elements had been turned into good. Additionally, his influence on others, whether individuals or the collective, had to be complete, including that he was able to serve as a role model for the power of repentance.
That is why it says that the "whole nation," i.e., all the individuals, and "all of Israel," i.e., the nation as a unit, should be influenced in their essence as a holy nation by the king who was anointed with the holy anointing oil. Thus, people should realize on all levels that David’s sin was forgiven.