Pope St. John Paul II
“In it is present ‘the blood of Christ, who through the eternal Spirit offered himself without blemish to God’ (Heb 9:14); the blood ‘poured out for many’ (Mk 14:24) ‘for the forgiveness of sins’ (Mt 26:28); the blood ‘which purifies your conscience from dead works’ (cf. Heb 9:14); the ‘blood of the covenant’ (Mt 26:28). When instituting the Eucharist, Jesus himself said: ‘This cup…is the new covenant in my blood’ (Lk 22:20; cf. 1 Cor 11:25), and he told the apostles: ‘Do this in remembrance of me’ (Lk 22:19).”
Source: Pope St. John Paul II, General Audience, September 13, 1989