הִנֵּה יָמִים בָּאִים נְאֻם ה’ וַהֲקִמֹתִי לְדָוִד צֶמַח צַדִּיק וּמָלַךְ מֶלֶךְ וְהִשְׂכִּיל וְעָשָׂה מִשְׁפָּט וּצְדָקָה בָּאָרֶץ
Behold, the days come, says Hashem, that I will raise unto David a righteous shoot; he will reign as king and prosper, and he will execute justice and righteousness in the land.
The fifteenth bracha of Shemoneh Esrei is Malchus Beis David, for the restoration of the Davidic dynasty. The Moshiach (Messiah) will be a descendant of King David and he is referred to as “tzemach David,” “the shoot of David.” (“Shoot” in the botanical sense, like a sprout.) The Radak on our verse explains that a shoot comes into the world alongside many others. Similarly, when the Moshiach reveals himself, the world will be full of comparably righteous people.