Matthew 2:17

Then was fulfilled that which was spoken by Jeremy the prophet, saying,

Then was fulfilled marks the killing of the innocent children in Bethlehem and its surrounding region as the fulfillment of what Jeremiah the prophet had spoken. Herod sent soldiers to kill children two years old and younger. He acted to assert his power over the Jews and to murder the infant prince he feared, hoping to destroy the king of Israel. The prophecy fulfilled was Jeremiah's vision given about six hundred years earlier of Rachel weeping for her children, picturing the lamentation, mourning and grief over their deaths. That sorrow was heard at Ramah, where mothers grieved their lost children and could not be comforted because they were gone.

The calamity followed the Jews' false teaching that Christ would rule an earthly empire in earthly glory. Their pride, hostility and false presentation of Christ and his mission stirred Herod's envy and hatred. It was permitted to humble the nation, and it filled their homes with mourning. The planners did not destroy the infant Christ. The slaughter was one of the last cruel acts of Herod's reign, and soon afterward Herod died a fearful death, unable to resist a power greater than his own.

The memory of Herod seeking to kill Jesus as an infant added to Joseph and Mary's sad and fearful anxiety for his safety when they turned back to Jerusalem sorrowing to seek him after losing him for a day on the return from Jerusalem.