We are taught this by the word _remembrance_, which our Saviour here uses. He says, "This do in remembrance of me." This means in remembrance of my sufferings for you. And _this_ is the most important word used by him when he established this sacrament. It is the governing word in the whole service. It is the word by which we must be guided in trying to understand what our Lord meant to teach us by all he did and said on this occasion. You know how it is when we are trying to understand the music to which a particular tune has been set. There is always one special note in a tune, which is called the _key-note_. The leader of a choir, when they are going to sing, will strike one of the keys of the organ, or the melodeon they are using, so as to give to each member of the choir the proper key-note of the piece of music they are to sing. It is very important for them to have this key-note, because they cannot have a proper understanding of what they are to do without it. This holy sacrament of the Lord's Supper is like a solemn song. And the key-note of the music to which the song is set is this word--_remembrance_. It teaches us that the sacrament of the Lord's Supper is a _memorial_ service. And, in going through the music to which the song of this service has been set, every note that we use must be a memorial note. And the language used by our blessed Lord when he established this Supper, or sacrament, must be explained in this way. When he broke the bread and gave it to his disciples, saying--"This is my body, which is given for you: this do in remembrance of me," he meant that we should understand him as saying--"This is the _memorial_ of my body." And when he gave them the cup, and said--"This is my blood of the New Testament," he meant that we should understand him as saying--"This is the _memorial_ of my blood." And we are sure that this was the meaning, for two reasons. One reason for believing this is that _this was the way in which similar words had been used in the Jewish Passover, which Jesus and his disciples were then keeping_. In the Passover service, when the head of the family distributed the bread, he always said--"This is the bread of affliction." When he distributed the flesh of the lamb, roasted for the occasion, he used to say--"This is the body of the Passover."