What did Jesus mean by "many" beneficiaries of His ensuing bloodshed?

In Matthew 26:27-28 (NRSVCE) we read: > Then he took a cup, and after giving thanks he gave it to them, saying, “Drink from it, all of you; for this is my blood of the covenant, which is poured out for many for the forgiveness of sins." Those words of Jesus are reproduced in the Eucharistic celebration of the Catholic Church. **My question is**: Why did Jesus use the words "for many" instead of "for all"? What are the connotations, including references to the OT, which the Catholic Church attribute to the word "many" as used by Jesus at the Last Supper?