Zechariah 12:10 describes the house of David and Jerusalem looking upon the one who has been pierced and mourning deeply for him. John 19:37 explicitly quotes this verse after recording the piercing of Jesus' side, making the crucifixion connection direct. Revelation 1:7 also reuses the imagery. The wording strikingly moves between 'me' and 'him,' which has important Christological significance for Christian readers, but the safest basis for the theme 'The Messiah would be both God and man' is the New Testament's explicit application of the pierced figure to Jesus.
The explanation preserves Zechariah's original prophetic setting while distinguishing explicit New Testament quotation from broader Christian typological or theological application.