The tombs broke open: At the moment of the death of Jesus, God’s kingdom broke into the world in a new way. His death destroyed the power of death and began the promise of final resurrection (see Isaiah 26:19; Daniel 12:2; 1 Corinthians 15:1–58; Colossians 1:18; Hebrews 2:14–15).
Some holy people were raised to life. But they may not have entered Jerusalem until after Jesus rose from the dead. Another view is that they were not raised until after the resurrection of Jesus, since Jesus is the “firstfruits” (the first to be raised, showing what will come for others; see 1 Corinthians 15:20, 23; Colossians 1:18). If this second view is correct, Matthew included the story to show the great impact of the death of Jesus.