I decided to reply in two parts since the first has so many verses about the day of the Lord.
I don't see how Matthew 12:8 has anything to do with Revelation 1:10 or all the verses about the day of the Lord. As for Jesus being the Lord of the sabbath, what isn't Jesus Lord of? Jesus is Lord of everything.
Now I think probably the early church started calling the first day of the week the Lord's Day, because that was the day of the resurrection.
Early on the first day of the week, while it was still dark, Mary Magdalene went to the tomb and saw that the stone had been removed from the entrance.
John 20:1
Afterwards on that day, the first day of the week, resurrected Jesus appeared to the Apostles.
You could have saved yourself some time with your posts here Brian. The Greek does
not say "
The day of the Lord" and it is not the same as "
The Lord's day" in the Greek. The former is in reference to the
second coming. John was not in the Spirit of the Lord's second coming. He was in the presence of Jesus in the heavenly Sanctuary (Revelation 1:12-17). The latter "
The Lord's day" in the Greek simply means the Lord's ownership of the day. Hence John was in the Spirit of the Lord's day. Therefore we can ask the question; What day is the Lord's day or the day the Lord claims ownership of?
Matthew 12:8
FOR THE SON OF MAN IS LORD EVEN OF THE SABBATH DAY
The answer given by the scriptures is pretty clear here.
.................
We can also add the following scriptures
Ezekiel 20:19-21[19], I am the Lord your God; walk in my statutes, and keep my judgments, and do them; [20], and keep holy
MY SABBATHS [my/God's seventh day rest/ my rest/God's rest]; and they shall be a sign between me and you, that you may know that I am the Lord your God. [21], notwithstanding the children rebelled against me: they walked not in my statutes, neither kept my judgments to do them, which if a man do, he shall even live in them;
THEY POLLUTED MY SABBATHS [my/god's seventh day rest/ my rest/god's rest]: THEN I SAID I WOULD POUR OUT MY FURY ON THEM TO ACCOMPLISH MY ANGER ON THEM IN THE WILDERNESS. [22], nevertheless I withdrew my hand, and worked for my name's sake, that it [my sabbath/ my rest/ god's rest] should not be polluted in the sight of the heathen, in whose sight i brought them forth.
Ezekiel 21:12-13 [12], moreover also I gave them
MY SABBATHS [my/god's seventh day rest/ my rest], to be a sign between me and them, that they might know that I am the Lord that sanctify them.[13], BUT THE HOUSE OF ISRAEL REBELLED AGAINST ME IN THE WILDERNESS: they walked not in my statutes, and they despised my judgments, which if a man do, he shall even live in them; and
MY SABBATHS [my/god's seventh day rest/ my rest] they greatly polluted: THEN I SAID I WILL POUR OUT MY FURY ON THEM IN THE WILDERNESS TO CONSUME THEM.
Isaiah 58:12-14 [12], and they that shall be of you shall build the old waste places: you shall raise up the foundations of many generations; and you shall be called, the repairer of the breach, the restorer of paths to dwell in. [13], if you turn away your foot from the sabbath, from doing your pleasure on
MY HOLY DAY [my/god's holy seventh day rest]; and call the sabbath [god's rest/seventh day rest] a delight, the holy of the Lord, honorable; and shall honor him, not doing your own ways, nor finding your own pleasure, nor speaking your own words: [14], then shall you delight yourself in the lord; and I will cause you to ride on the high places of the earth, and feed you with the heritage of Jacob your father: for the mouth of the Lord has spoken it.
...............
John therefore according to the scriptures I believe was in the Spirit of the Sabbath day. The reference to "
the Lords day" is John acknowledging Jesus as the creator God of Heaven and earth.
Hope this is helpful