Well, unless I’m just blind, it’s not mentioned in Matthew 26

Mark 14, it is only mentioned in verse 24, which says His blood is poured out for many. The issue with this is that it would work both for the traditional understanding (poured out to pay for sin) and for the understanding I am trying to argue against (that Christ’s death was fulfilling a covenantal duty, not paying for sin, and that paying for sin was added on with the epistles).

Luke 22:19 & 20 has the same issue as the Mark passage for the argument at hand, He says they are for people, but nothing about it being for the forgiveness of sins.

John doesn’t have the Eucharist in it.