Verse 37 of Doctrine and Covenants 20 begins a series of instructions on baptism, ordination, priesthood offices, and the sacrament. Much of this was drawn directly from the Book of Mormon, especially the book of Moroni
(italics have been added to highlight similarities):
The first part of verse 37 explains some initial requirements for baptism: “All those who humble themselves before God, and desire to be baptized, and come forth with broken hearts and contrite spirits, and witness before the church that they have truly repented of all their sins … shall be received by baptism into his church.” This is almost identical to Moroni 6:2: “Neither did they receive any unto baptism save they came forth with a broken heart and a contrite spirit, and witnessed unto the church that they truly repented of all their sins.”
Further in D&C 20:37 we read: “and are willing to take upon them the name of Jesus Christ, having a determination to serve him to the end.” This matches up with the next verse by Moroni: “And none were received unto baptism save they took upon them the name of Christ, having a determination to serve him to the end” (Moroni 6:3).
And verse D&C 20:37 ends by saying: “and truly manifest by their works that they have received the Spirit of Christ unto the remission of their sins.” This is similar, though not identical, to portions of verses 1 and 4 in Moroni 6: “they were not baptized save they brought forth fruit meet that they were worthy of it” (verse 1) and “after they had been received unto baptism, and were wrought upon and cleansed by the power of the Holy Ghost” (verse 4).
The next portion of D&C 20, dealing with the duties of the various offices of the priesthood, does not show up in Moroni until verse 60. However, in the middle of these duties is some instruction to the elders on how to conduct their meetings. “The elders are to conduct the meetings as they are led by the Holy Ghost, according to the commandments and revelations of God” (D&C 20:45). See Moroni’s description in Moroni 6:9: “And their meetings were conducted by the church after the manner of the workings of the Spirit, and by the power of the Holy Ghost; for as the power of the Holy Ghost led them whether to preach, or to exhort, or to pray, or to supplicate, or to sing, even so it was done.”
D&C 20:60 “Every elder, priest, teacher, or deacon is to be ordained according to the gifts and callings of God unto him; and he is to be ordained by the power of the Holy Ghost, which is in the one who ordains him.” Moroni 3:4 reads “And after this manner did they ordain priests and teachers, according to the gifts and callings of God unto men; and they ordained them by the power of the Holy Ghost, which was in them.
Sacrament prayers and instructions were taken from the Book of Mormon as well. D&C 20:75 directs the church to “meet together often to partake of bread and wine in remembrance of the Lord Jesus.” Moroni 6:6 “And they did meet together oft to partake of bread and wine, in remembrance of the Lord Jesus.” The sacrament prayers and “manner” in D&C 20:76-79 are taken directly from Moroni 4:1-3 and Moroni 5:1-2.
Finally, D&C 20:80-83 provides instruction regarding those who transgress “Any member of the church Christ transgressing or being overcome in a fault, shall be dealt with as the scriptures direct,” with the possibility of “their names [being] blotted out of the general church record of names. Moroni 6:7-8 is similar, and may even be among the “scriptures” that D&C 20 is referring to: “And they were strict to observe that there should be no iniquity among them; and whoso was found to commit iniquity, and three witness of the church did condemn them before the elders, and if they repented not, and confessed not, their names were blotted out, and they were not numbered among the people of Christ. But as oft as they repented and sought forgiveness, with real intent, they were forgiven.”