In order to a better understanding of all that the Gospels tell us of the Last Supper, it will be well to see how the Jews at that time kept the Passover.
In the first place, on the day when the Paschal Lamb was to be killed and eaten, the Jews were to put away out of their houses all leaven or yeast, and live for a whole week on cakes made of unleavened dough: hence the Feast of the Passover was also called the "Feast of unleavened bread."
1. When the guests were assembled in the evening to eat the Passover, the ceremonies began, by the master of the house giving to each one a cup of wine mixed with water, saying at the same time, "Blessed be He that created the fruit of the vine": then they all gave thanks and drank the wine.
2. All the guests after drinking the wine, washed their hands; and then the three things ordered by the Law of Moses, were placed on the table before the master of the house. These three things were, the Paschal Lamb roasted whole; two cakes of unleavened bread; and a dish of bitter herbs. To these were added the remains of the peace-offerings offered the day before, and some other meats; also a thick sour sauce, intended to remind the Jews of the bricks made by their forefathers in Egypt.
The master of the house, or whoever took the direction of the feast, then ate, and gave to each of the guests a small piece of lettuce; at the same time blessing God for the fruits of the earth; afterwards each person present, ate a bit of the unleavened bread dipped in the bitter herbs.
3. In the third place, all the dishes were taken off the table, and the children, who were not of age to keep the feast, were called in: the meaning of the Feast was then explained to them, in obedience to the commandment of the Lord, spoken by Moses, saying, "And it shall come to pass when ye be come to the land which the Lord will give you, and your children shall say unto you, What mean ye by this service? that ye shall say, It is the sacrifice of the Lord's Passover, Who passed over the houses of the children of Israel in Egypt, when He smote the Egyptians and delivered our houses."
4. After the young people had been duly taught, the supper was, in the fourth place, again set upon the table. Each person then, in turn, lifted up the bitter herbs and the unleavened cakes, and afterwards joined in declaring, that they ate them in remembrance of the bondage in Egypt, and the deliverance from it: then they praised God, by singing the 113th and 114th Psalms; and having blessed the Lord, a second cup of wine was drunk.
5. In the fifth place, the guests again washed their hands; and then the master of the family took the two unleavened cakes, broke one of them into pieces, and placed the broken pieces on the top of the whole cake: after this, he blessed it; and each person taking one of the broken pieces with some of the bitter herbs, dipped them into the sour sauce, and ate them; they then blessed God again. Thanks were now given over the remains of the yesterday's peace-offering, and some of that eaten. The next step was to give thanks over the Paschal Lamb, of which all partook. The Passover Feast was now, in fact, finished; but the Jews made the supper last longer, by eating any other food they liked; always taking care to finish by swallowing a little morsel of lamb, as after partaking of that, they were not supposed to eat anything more that night.
6. In the sixth place, the hands were washed for the third time; and the master of the house said a blessing over a third cup of wine, which was then drunk by each guest. This third cup of wine was commonly called the "Cup of Blessing." A fourth cup of wine was then mixed with water; and over this, certain Psalms, from the 115th to 118th inclusive, were sung; and then a prayer concluded the whole ceremony.