Roman Catechism 18.62

Chapter 18 — Part II: The Sacraments — The Holy Eucharist

Section 62. Here, therefore, rather than at the consecration of His body, is appropriately commemorated the Passion of our Lord, by the words. which shall be shed for the remission of sins. For the blood, separately consecrated, serves to place before the eyes of all, in a more forcible manner, the Passion of our Lord, His death, and the nature of His sufferings.