The synoptic Gospels seem to suggest that the Last Supper was a Passover meal, whereas John is clear that the Passover began at sundown of the day when Christ was crucified. John’s account seems to bear the most historical verisimilitude: a criminal would certainly not be crucified during the Passover feast itself. Additionally, the Johannine imagery is strong: the day before Passover was a Preparation Day, and between 3:00–5:00 the Paschal lambs were slaughtered in the Temple. Accordingly, Jesus died on the cross at 3:00 at the very moment the first Passover lamb was sacrificed. Although scholars have proposed a number of ways to resolve the apparent discrepancy, the most likely answer is that Jesus, knowing that he would be dead before Passover began, celebrated the feast early with his friends.
And when the hour was come, he sat down, and the twelve apostles with him. And he said unto them, “With desire I have desired to eat this passover with you before I suffer: For I say unto you, I will not any more eat thereof, until it be fulfilled in the kingdom of God.” (Luke 22:14–16; see D&C 27:5ff.)
The Gospels record two important ordinances at the Last Supper: the Sacrament of the Lord’s Supper in the Synoptics and the Washing of Feet in John. The earliest reference to the institution of the sacrament in the New Testament is actually in the letters of Paul, which were written before any of the gospels:
For I have received of the Lord that which also I delivered unto you, That the Lord Jesus the same night in which he was betrayed took bread: And when he had given thanks, he brake it, and said, Take, eat: this is my body, which is broken for you: this do in remembrance of me. After the same manner also he took the cup, when he had supped, saying, This cup is the new testament in my blood: this do ye, as oft as ye drink it, in remembrance of me. (1 Corinthians 11:23–26)
John’s omission of the sacrament is surprising, but sacramental imagery is woven throughout the body of his gospel (e.g. the Bread of Life Discourse, Jesus as the Fountain of Living Water, the Vine, etc.). John does, however, preserve an account of Jesus washing his disciples’ feet. Although a priesthood ordinance, one aspect of which is alluded to in D&C 88:139–141, the significance of it in the narrative of the Gospel of John is as an act of service and love:
Jesus knowing that the Father had given all things into his hands, and that he was come from God, and went to God; He riseth from supper, and laid aside his garments; and took a towel, and girded himself. After that he poureth water into a bason, and began to wash the disciples’ feet, and to wipe them with the towel wherewith he was girded. . . . So after he had washed their feet, and had taken his garments, and was set down again, he said unto them, “Know ye what I have done to you? Ye call me Master and Lord: and ye say well; for so I am. If I then, your Lord and Master, have washed your feet; ye also ought to wash one another’s feet. For I have given you an example, that ye should do as I have done to you. Verily, verily, I say unto you, The servant is not greater than his lord; neither he that is sent greater than he that sent him. If ye know these things, happy are ye if ye do them.” (John 13:3–5, 12–17)
In accordance with this example it is the practice in the Roman Catholic and some other churches for bishops or spiritual leaders to wash the feet of token members of their flock on Maundy Thursday. Similar practices were performed by some European kings, who would wash the feet of peasants and make distributions of coins to the assembled crowds. In the Church today, the ordinance itself is reserved for sacred occasions, but the example of loving and serving others is lived every day.