Who are the “Saints” and the “Many” in Matthew 27:52-53?

A Strange sidenote in the Gospel of Matthew documents resurrected "Saints" visible to "Many" in Jerusalem :

Matthew 27:52-53 [KJV]

[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.”

• We know from Nehemiah 11:1 that the "Holy City" (עִ֣יר הַקֹּ֔דֶשׁ) refers to Yerushalaim (יְרוּשָׁלָ֑םִ).

If Jerusalem is "the Holy City", Who are the "Saints" and the "Many" in Matthew 27:52-53?