Jesus instituted the sacrament at the last Supper, Luke 22:19-20, Matthew 26:26-29, and Mark 14:22-25. Jesus also introduced the sacrament to the people in the Americas, 3 Nephi 18:1-11. Jesus broke bread for the disciples but he had the disciples break bread bread for the multitude training them in what they need to do. On the second day that Jesus appeared to the Nephites he also administered the sacrament and explained it's meaning, 3 Nephi 20:3-9.
Two of His disciples recognized Jesus when he broke bread with them at Emmaus, Luke 24:29-31 and Luke 24:35.
In the sacrament we witness to God that we will 1) take upon us Jesus' name, 2) always remember him, and 3) keep his commandments in turn we are promised to have His spirit to be with us, D&C 20:77
The Sacrament prayers that we use in the Church today are in the Doctrine and Covenants,
D&C 20:77 and
D&C 20:79.
Except we use water instead of wine see,
D&C 27:2.
The versions in the Book of Mormon are exactly the same except for punctuation and a "hath" instead of a "has"
Moroni 4:3 and
Moroni 5:2.
The blessing on the bread in the Book of Mormon is "he hath given them" and the Doctrine and Covenants is "he has given them."
It is the priest's duty to administer the sacrament,
D&C 20:46,
but the teachers and deacons don't have the authority to administer the sacrament,
D&C 20:58.
There are a number of places in scripture where breaking bread is mentioned.
The early Saints continued steadfastly in the apostles' doctrine and in breaking of bread,
Acts 2:42.
The early saints broke "bread from house to house,"
Acts 2:46-47.
Paul broke bread with the saints in Troas,
Acts 20:7 and
Acts 20:11.
On the ship just before it wrecked Paul broke bread with them all,
Acts 27:35.
After teaching the people in America for 3 days he visited and broke bread with them often,
3 Nephi 26:13.
If we partake worthily of the sacrament and endure to the end we can be saved,
Mormon 9:29-30.
Those that eat the flesh and drink the blood of Christ will be raised up at the last day,
John 6:48-58. This scripture occurred early in the Lord's ministry pointing to what would later be the ordinance of the sacrament.
The Sacrament is the communion of Christ,
1 Corinthians 10:16.
Paul explains the sacrament to the Corinthians and warns about taking it unworthily,
1 Corinthians 11:23-29.
Partaking of the Sacrament unworthily brings damnation upon a person,
3 Nephi 18:28-29
The Sacrament was an Important Part of Early Church Worship
Those That Partake Worthy Will be Blessed