Zechariah — Chapter 12

Et effundam super domum David et super habitatores Ierusalem spiritum gratiae

'And I will pour upon the house of David and upon the inhabitants of Jerusalem the spirit of grace and of prayers; and they shall look upon me whom they have pierced; and they shall mourn for him as one mourneth for an only son.' John 19:37 cites this at the piercing of Christ's side on the Cross, identifying Jesus as the one pierced. À Lapide gives a Trinitarian exegesis: 'They shall look upon ME' (the Father speaks) 'whom they have pierced'—but the Father was not pierced; therefore the text teaches the consubstantiality of Father and Son. He also reads the mourning as the Church's Good Friday liturgy and the future conversion of Israel at the Parousia.