Zechariah 12:10

The Lord also promised to pour out on the Davidic rulers and the inhabitants of Jerusalem, representing all the Israelites, a spirit of remorse. Grace would be the motive for this outpouring, and supplication to God (for what the Jews had done to their Messiah) would be the result. This God-given conviction would cause them to mourn when they looked (in faith) to Him (better than on Him) whom they had formerly pierced (i.e., slain; cf. Numbers 21:9; Isaiah 45:22; Isaiah 53:5; John 3:14-15; John 19:34).

"It is not so much a mourning for the act committed, but for the Person involved. Compare John 19:37; Revelation 1:7." [Note: Feinberg, God Remembers, p. 231.]

"The idea is that they will humble themselves and recognize that they were saved by another whom they pierced." [Note: Smith, p. 277.]

They would mourn as one mourns over the death of one’s only (beloved, cf. Genesis 22:2; Jeremiah 6:26; Amos 8:10) son or his or her firstborn son.

"It is a picture of penitence as vivid and accurate as any found anywhere in the Scriptures." [Note: Chambers, p. 94, in Lange’s commentary.]

The Jews will do this either just before the Messiah returns to the earth or when He returns to the earth (cf. Isaiah 27:9; Isaiah 59:20-21; Jeremiah 31:31-37; Amos 9:11-15; Romans 11:25-27; Revelation 1:7). The spirit in view will be a result of the ministry of the Holy Spirit who conveys grace (compassion; cf. Hebrews 10:29) and calls forth supplication (prayer; cf. Isaiah 32:15; Isaiah 44:3; Isaiah 59:20-21; Jeremiah 31:31; Jeremiah 31:33; Ezekiel 36:26-27; Ezekiel 39:29; Joel 2:28-29). The coming of the messianic kingdom is contingent on Israel’s repentance, God’s sovereign control, and the Spirit’s enabling grace. [Note: See Stanley D. Toussaint and Jay A. Quine, "No, Not Yet: The Contingency of God’s Promised Kingdom," Bibliotheca Sacra 164:654 (April-June 2007):131-47.]

The unusual combination "they will look to Me whom they have pierced" and "they will mourn for Him" suggests two different individuals, but the deity of the Messiah solves this problem. Yahweh Himself would suffer for the people in the person of Messiah. The suffering could be figurative (they wounded His holiness) or substitutionary (He died in place of others). Other references to this text point to a substitute suffering (e.g., John 19:37; Revelation 1:7; cf. Isaiah 53:5; Isaiah 53:8).

". . . like Thomas their excruciating and inexpressibly penetrating cry of deepest contrition will be, ’My Lord and my God!’ (John 20:28)." [Note: Unger, p. 217.]