16 Does any one perchance flatter himself with this notion, that although in the morning, water alone is seen to be offered, yet when we come to supper we offer the mingled cup? But when we sup, we cannot call the people together to our banquet, so as to celebrate the truth of the sacrament in the presence of all the brotherhood. But still it was not in the morning, but after supper, that the Lord offered the mingled cup. Ought we then to celebrate the Lord's cup after supper, that so by continual repetition of the Lord's supper we may offer the mingled cup? It behooved Christ to offer about the evening of the day, that the very hour of sacrifice might show the setting and the evening of the world; as it is written in Exodus, “And all the people of the synagogue of the children of Israel shall kill it in the evening.” And again in the Psalms, “Let the lifting up of my hands be an evening sacrifice.” But we celebrate the resurrection of the Lord in the morning.
Source: The Epistles of Cyprian (New Advent)