Because Dovid Hamelech is דָוִד מֶלֶךְ יִשְּרָאֵּל חַי וְּקַיָם “Dovid, HaMelech, King of Israel, lives and endures.” Dovid the King Moshiach (and is the Final redeemer).
And every one of B’nei Yisroel has within him a tiny bit just as they have a spark of Rabi Shimon Ben Yochoi and a spark from Moshe Rabeinu (First redeemer). From this it is understood that this is relevant to every single Jew. And this is why Yisroel is called a Chosson whilst the Torah is called a Kallah.
The second aspect is: that the whole existence of Yisroel is the Torah. As is illustrated in the well-known parable that Rabbi Akivah gave that the existence of
Final redeemer: And because these Inyonim with Dovid Hamelech is Chai Vekayom, and that he is the king Moshiach, and he is the redeemer of B’nei Yisroel. Therefore, the way it is with Dovid Hamelech is relevant to every single Jew.
A tiny bit: A small bit of a small bit of the Torah that Dovid Hamelech studied.
And this is why: Because it is Yisroel who is rooted in Atzmus, and therefore in this case Yisroel is the Mashpia and the Torah is the lower level being brought up to Atzmus by Yisroel.
The second aspect: In the unity of the B’nei Yisroel and the Torah. Where the first aspect has been the that you cannot take the B’nei Yisroel out of the Torah.
Parable Rabbi Akiva gave: Regarding the strong connection of B’nei Yisroel and Torah. In the Talmud Brochos 61b: The Sages taught: One time, after the Bar-Kochba rebellion, the evil empire of Rome decreed that the B’nei Yisroel may not engage in the study and practice of Torah. Pappos ben Yehuda came and found Rabbi Akiva, who was convening assemblies in public and engaging in Torah study. Pappos said to him: Akiva, are you not afraid of the empire? Rabbi Akiva answered him: I will relate a parable. To what can this be compared? It is like a fox walking along a riverbank when he sees fish gathering and fleeing from place to place. The fox said to them: From what are you fleeing? They said to him: We are fleeing from the nets that people cast upon us. He said to them: Do you wish to come up onto dry land, and we will reside together just as my ancestors resided with your ancestors? The fish said to him: You are the one of whom they say, he is the cleverest of animals? You are not clever; you are a fool. If we are afraid in the water, our natural habitat which gives us life, then in a habitat that causes our death, all the more so. The moral is: So too, we Jews, now that we sit and engage in Torah study, about which it is written: “For that is your life, and the length of your days” (Devorim 30:20), we fear the empire to this extent; if we proceed to sit idle from its study, as its abandonment is the habitat that causes our death, all the more so will we fear the empire.
