וְ֠עַתָּה כֹּֽה־תֹאמַ֞ר לְעַבְדִּ֣י לְדָוִ֗ד כֹּ֤ה אָמַר֙ יְהוָ֣ה צְבָא֔וֹת אֲנִ֤י לְקַחְתִּ֙יךָ֙ מִן־הַנָּוֶ֔ה מֵאַחַ֖ר הַצֹּ֑אן לִֽהְי֣וֹת נָגִ֔יד עַל־עַמִּ֖י עַל־יִשְׂרָאֵֽל׃
E ora, così dirai al mio servo, a Davide: Così ha detto il Signore degli eserciti: Io ti ho preso dal pascolo, da dietro le pecore, perché tu fossi principe sul mio popolo, su Israele.
Rashi
when the basest to the sons of men is elevated Heb. כרם זלות לבני אדם [They walk on all sides] because of their envy, for they are jealous of my greatness, that I was taken from behind the sheep to be a king. This is the interpretation of כרם זלות לבני אדם: when a man considered by the sons of men to be base is elevated. This is on the order of the passage elsewhere (below 118:22): “The stone that the builders rejected became a cornerstone.” The Midrash Aggadah interprets it concerning Israel in the future, when they will be elevated. [Unknown Midrashic source] Menachem interprets כרם זלות לבני אדם (pp. 78, 164): like a gluttonous wild ox to devour the sons of men. Accordingly, כרם is rendered: like a רים or ראם, and זלות is like (Deut. 21:20) זולל וסבא, “a glutton and a drunkard.” The following is its interpretation: The wicked walk on all sides around the poor man; the wicked walk to swallow him for naught, as a wild ox to swallow the sons of men.
Rashi
Even though in his own kingdom. Since he reigned over man, the poor one was born; who was better than he, and who came out of purity, not out of the filth of the womb. So it was expounded in the Midrash. Another explanation: “Better a poor but wise child, etc.” [to be understood] according to its apparent meaning, “[one] who no longer knows to be vigilant,” for he has already aged in his wickedness and foolishness. “Even though he [the child] emerged from prison to be king.” For the poor child; it will ultimately be said about him that he went out to reign from the midst of his affliction and from his prison cell, for the samech of הָסוּרִים is punctuated without a dagesh, which is the equivalent of הָאֲסוּרִים. (Some editions: As in, “And no Arab will pitch יַהֵל his tent there,”23Yeshayahu 13:20. which is the same as “יַאֲהֵל.”) For so we find that Yoseif reigned following his being freed from prison, and so Dovid, “I have taken you from the sheepcote, from following the flocks.”24II Shmuel 7:8.