When Jesus gave the disciples the cup, what did he say it was?

Answer: My blood

Jesus said, "This is My blood of the covenant, which is poured out for many for the forgiveness of sins." (KJV: new testament)

“Then He took the cup, gave thanks, and gave it to them, saying, “Drink from it, all of you. This is My blood of the covenant, which is poured out for many for the forgiveness of sins.”— Matthew 26:27-28 (BSB)