All things bear record · Doctrine and Covenants
3 witnesses of Christ here, and 5 further echoes from the reading.
Behold, thus saith the Lord your God unto you, O ye elders of my church, hearken ye and hear, and receive my will concerning you. Doctrine and Covenants 64:1
Jesus Christ speaks to the elders of "my church"; the Church bears His name and He directs it.
How we know: a footnote points to Him
There are those among you who have sinned; but verily I say, for this once, for mine own glory, and for the salvation of souls, I have forgiven you your sins. Doctrine and Covenants 64:3–4
Only Christ, who paid for sins, can say "I have forgiven you." He forgives for the salvation of souls and gives His people the kingdom.
Nevertheless, he has sinned; but verily I say unto you, I, the Lord, forgive sins unto those who confess their sins before me and ask forgiveness, who have not sinned unto death. Doctrine and Covenants 64:7
Christ sets the terms of His mercy: confess to Him and ask, and He forgives.
My disciples, in days of old, sought occasion against one another and forgave not one another in their hearts; and for this evil they were afflicted and sorely chastened. Doctrine and Covenants 64:8–10
"My disciples, in days of old" are Jesus' own followers in His mortal ministry; the same Master now teaches that forgiving others is required of everyone.
Lawgiver — the One who gives the law
And this ye shall do that God may be glorified—not because ye forgive not, having not compassion, but that ye may be justified in the eyes of the law, that ye may not offend him who is your lawgiver— Doctrine and Covenants 64:13
"Him who is your lawgiver" is the Lord Himself, who elsewhere says "I am your lawgiver" and "I am he that gave the law."
Son of Man — Son of Man of Holiness, the Son of the Father (Moses 6:57)
Behold, now it is called today until the coming of the Son of Man, and verily it is a day of sacrifice, and a day for the tithing of my people; for he that is tithed shall not be burned at his coming. Doctrine and Covenants 64:23
Christ calls the time before His Second Coming "today": a season to sacrifice and pay tithing so we are prepared when He comes.
How we know: the verse itself names Him · a footnote points to Him · a Church study aid lists it
Lord of Hosts — Jehovah, Lord of the armies of heaven
For after today cometh the burning—this is speaking after the manner of the Lord—for verily I say, tomorrow all the proud and they that do wickedly shall be as stubble; and I will burn them up, for I am the Lord of Hosts; and I will not spare any that remain in Babylon. Doctrine and Covenants 64:24–25
Jesus speaks Malachi's prophecy in the first person: He is the Lord of Hosts who will cleanse the earth at His coming.
How we know: the verse itself names Him
For, behold, I say unto you that Zion shall flourish, and the glory of the Lord shall be upon her; Doctrine and Covenants 64:41–42
Isaiah's picture of the Lord's glory resting on His people is applied to latter-day Zion, which gathers the nations to Christ.