10. Future conversion of the Jews is to flow from an extraordinary outpouring of the Holy Spirit (Jer 31:9, 31-34; Eze 39:29).
      spirit of grace . . . supplications--"spirit" is here not the spirit produced, but THE HOLY SPIRIT producing a "gracious" disposition, and inclination for "supplications." CALVIN explains "spirit of grace" as the grace of God itself (whereby He "pours" out His bowels of mercy), "conjoined with the sense of it in man's heart." The "spirit of supplications" is the mercury whose rise or fall is an unerring test of the state of the Church [MOORE]. In Hebrew, "grace" and "supplications" are kindred terms; translate, therefore, "gracious supplications." The plural implies suppliant prayers "without ceasing." Herein not merely external help against the foe, as before, but internal grace is promised subsequently.
      look upon me--with profoundly earnest regard, as the Messiah whom they so long denied.
      pierced--implying Messiah's humanity: as "I will pour . . . spirit" implies His divinity.
      look . . . mourn--True repentance arises from the sight by faith of the crucified Saviour. It is the tear that drops from the eye of faith looking on Him. Terror only produces remorse. The true penitent weeps over his sins in love to Him who in love has suffered for them.
      me . . . him--The change of person is due to Jehovah-Messiah speaking in His own person first, then the prophet speaking of Him. The Jews, to avoid the conclusion that He whom they have "pierced" is Jehovah-Messiah, who says, "I will pour out . . . spirit," altered "me" into "him," and represent the "pierced" one to be Messiah Ben (son of) Joseph, who was to suffer in the battle with Cog, before Messiah Ben David should come to reign. But Hebrew, Chaldee, Syriac, and Arabic oppose this; and the ancient Jews interpreted it of Messiah. Ps 22:16 also refers to His being "pierced." So Joh 19:37; Re 1:7. The actual piercing of His side was the culminating point of all their insulting treatment of Him. The act of the Roman soldier who pierced Him was their act (Mt 27:25), and is so accounted here in Zechariah. The Hebrew word is always used of a literal piercing (so Zec 13:3); not of a metaphorical piercing, "insulted," as MAURER and other Rationalists (from the Septuagint) represent.
      as one mourneth for . . . son-- (Jer 6:26; Am 8:10). A proverbial phrase peculiarly forcible among the Jews, who felt childlessness as a curse and dishonor. Applied with peculiar propriety to mourning for Messiah, "the first-born among many brethren" (Ro 8:29).

JFB.