This entire chapter's context is full of a description of the "FIRST resurrection" event, when
the many Matthew 27:52-53 saints came out of their graves on the same day that "Christ the First-fruits" arose from the dead. There were
144,000 of those Jewish OT tribal members who were raised from their graves around Jerusalem on that same day, who were also called
"The First-fruits unto God and the Lamb" in
Revelation 14:4. These 144,000 Jewish tribal members shared the same "First-fruits" title with Christ, because they shared the same resurrection day in AD 33. This was the fulfillment of the ancient Mosaic rite in
Leviticus 23:10-12 of the sheaf handful of Passover First-fruits of the barley harvest being waved in the temple (representing the many resurrected
Matt. 27:52-53 saints), which was offered
along with a single He-Lamb without blemish (representing Christ).