Saints resurrected BEFORE Jesus

It says in Matthew 27 that many saints were resurrected when Jesus died but also 1 Corinthians says that Jesus was the first of fruits to be resurrected? Can someone explain this please? God bless and Shalom

Matthew 27:51-53 KJV [51] And, behold, the veil of the temple was rent in twain from the top to the bottom; and the earth did quake, and the rocks rent; [52] and the graves were opened; and many bodies of the saints which slept arose, [53] and came out of the graves after his resurrection, and went into the holy city, and appeared unto many.

1 Corinthians 15:20 KJV [20] But now is Christ risen from the dead, and become the firstfruits of them that slept.