How Sunday Came to be Called The Lord's Day
All Bible texts quoted are from the Douay Rheims Bible unless otherwise noted.
"And on the seventh day God ended his work which he had made: and he rested on the seventh day from all his work which he had done. And he blessed the seventh day, and sanctified it: because in it he had rested from all his work which God created and made." Genesis 2:2-3.
Notice, this happened on the seventh day of creation. Adam and Eve had been created but Abraham, Isaac and Jacob had not been born so there were no "children of Israel" nor were there any Hebrews or Jews.
"Remember that thou keep holy the sabbath day. Six days shalt thou labour, and shalt do all thy works. But on the seventh day is the sabbath of the Lord thy God: thou shalt do no work on it, thou nor thy son, nor thy daughter, nor thy manservent, nor thy maidservant, nor thy beast, nor the stranger that is within thy gates. For in six days the Lord made heaven and earth, and the sea, and all things that are in them, and rested on the seventh day: therefore the Lord blessed the seventh day and sanctified it." Exodus 20: 8-11.
The above text is part of the Ten Commandments written on tables of stone and given to Moses on Mt. Sinai. At that time there was no body of people called Jews. The word Jew, per Noah Webster's 1828 American Dictionary of the English Language, is a contraction of the word Judah or Judas and was applied to the descendants of Abraham much later. The commandment regarding the Sabbath day was included along with all the others that included the ones about not killing, stealing, etc.
"Gather it six days: but on the seventh day is the sabbath of the Lord, therefore it shall not be found. And the seventh day came: and some of the people going forth to gather, found none." Exodus 16:26-27.
The above text is about the "Manhu" or as other Bibles read, Manna, which was provided Sunday through Friday as food for the children of Israel every week for 40 years and never on Saturday, the Lord's Sabbath. Notice also that the mention of God's Sabbath came before the law was written on tables of stone by God on Mt. Sinai as recorded in Exodus 20. The weekly cycle of seven days originated at the time of creation; it is also clear that Moses knew what day was holy before he was given the law on the tables of stone. If there had ever been any confusion regarding which was the seventh day of the week, and there wasn't, God cleared that up by not giving "Manhu" on his Sabbath.
"At that time Jesus went through the corn on the Sabbath: and his disciples being hungry, began to pluck the ears and to eat. And the Pharisees seeing them, said to him: Behold thy disciples do that which is not lawful to do on the Sabbath days. But he said to them: Have you not read what David did when he was hungry, and they that were with him: How he entered into the house of God and did eat the loaves of proposition, which it was not lawful for him to eat, nor for them that were with him, but for the priests only? And if you knew what this meaneth: I will have mercy, and not sacrifice: you would never have condemned the innocent. For the Son of man is Lord even of the Sabbath." Matthew 12:1-4, 7-8.
This text is clearly about the seventh day Sabbath and Jesus says he is the "Lord" of it. So, apparently one could call the seventh day of the week the Lord's Day.
"In the beginning was the Word, and the Word was with God, and the Word was God. The same was in the beginning with God. All things were made by him: and without him was made nothing that was made. And the Word was made flesh, and dwelt among us, (and we saw his glory, the glory as it were of the only begotten of the Father,) full of grace and truth." John 1:1-3, 14.
The above passages clearly refer to Jesus who is also the Word. He made all things including his day of rest.
"Here is the patience of the saints, who keep the commandments of God, and the faith of Jesus." Apocalypse (Revelation in Protestant Bibles) 14:12
So John, in prophetic vision, saw that keeping the commandments of God was still important. Maybe the change in God's holy day of rest came later?
"Q. Which is the Sabbath day?
The above is from The Convert's Catechism of Catholic Doctrine by Rev. Peter Geiermann, C.SS.R on page 50.
Here are some quotations from A Doctrinal Catechism by Stephen Keenan with the imprimatur of John Cardinal McCloskey, Archbishop of New York. It was written back in the mid 1800s but is available as a reprint (ISBN 978-1-331-22670-3). On page 101, proof is requested that Protestants are not guided by Scripture. Part of the answer is:
A. Saturday is the Sabbath day.
Q. Why do we observe Sunday instead of Saturday?
A. We observe Sunday instead of Saturday because the Catholic Church transferred the solemnity from Saturday to Sunday."
"They should, if Scripture were there only rule, wash the feet of one another, according to the command of Christ in the 13th chap. of St. John ;-they should keep, not the Sunday, but the Saturday, according to the commandment, "Remember thou keep holy the SABBATH-day ;" for this commandment has not, in Scripture, been changed or abrogated ; -they should receive, what they call the sacrament, after supper, and not in the morning, because Christ instituted that sacrament at night, and his Apostles received it after supper ;-they should not eat blood or strangled meat, because the Apostles forbid it in the 15th chap. of the Acts ;-they should not baptize infants, as there is no example in Scripture to justify such a practice."
Yes, that really is one long sentence and the spacing between the word and the semicolon is as it appears in the catechism. Punctuation and spacing was apparently different back in the 1880s. The above catechism on page 181 tells what to answer to a Protestants who speaks against fasts and abstinences.
"Ask him why he keeps Sunday, and not Saturday, as his day of rest, since he is unwilling either to fast or to abstain. If he reply that the Scripture orders him to keep the Sunday, but says nothing as to fasting and abstinence, tell him the Scripture speaks of Saturday or the Sabbath, but gives no command anywhere regarding Sunday or the first day of the week. If, then, he neglects Saturday as a day of rest and holiness, and substitutes Sunday in its place, and this merely because was the usage of the ancient Church, should he not, if he wishes to act consistently, observe fasting and abstinence, because the ancient Church so ordained ?"
Some more from the above catechism (page 174).
"Q. Have you any other way of proving that the Church has power to institute festivals of precept ?
A secular authoritative source, Noah Webster's 1828 American Dictionary of the English language, confirms what these catechisms say. Under SAB'BATH, it says:
A. Had she not such power, she could not have done that in which all modern religionists agree with her ;-she could not have substituted the observance of Sunday the first day of the week, for the observance of Saturday the seventh day, a change for which there is no Scriptural authority."
"The day which God appointed to be observed by the Jews as a day of rest from all secular labor or employments, and to be kept holy and consecrated to his service and worship. This was originally the seventh day of the week, the day on which God rested from the work of creation ; and this day is still observed by the Jews and some christians, as the sabbath. But the christian church very early begun and still continue to observe the first day of the week, in commemoration of the resurrection of Christ on that day, by which the work of redemption was completed. Hence it is often called the Lord's day. The heathen nations in the north of Europe dedicated this day to the sun, and hence their christian descendants continue to call the day Sunday. But in the United States, some christians have to a great extent discarded the heathen name, and adopted the Jewish name sabbath."
The words Sabbath, Christian and Christians are not capitalized in the above dictionary. As the above quotation says, the Sabbath is the day God rested from his work of creation and you can read in Genesis 2:2-3 that the day was sanctified at that time. Creation happened long before there were any Children of Israel or Jews.
Now consider this Bible text.
"For as the new heavens, and the new earth, which I will make to stand before me, saith the Lord: so shall your seed stand, and your name. And there shall be month after month, and sabbath after sabbath: and all flesh shall come to adore before my face, saith the Lord." Isaiah 66:22-23.
The above text refers to the new heavens and the new earth that aren't yet made. There is no text in the Holy Bible that would show that Jesus changed his holy day of rest from the seventh day of the week to any other day. The text was taken from the Douay Rheims Bible of 1582-1610 that I have on my iPhone as an app. My print version of that Bible has neither verse 23 nor 24 of Isaiah 66. Both the Revised Standard Version (RSV) and the New Revised Standard Version (NRSV) of the Bible received the imprimatur of the Roman Catholic Church. The only difference between the ones marketed to Protestants and the ones marketed to Roman Catholics is the presence of the deuterocanonical books (which compose the Apocrypha and non-canonical books) in the ones marketed to Roman Catholics. I have the NRSV marketed to Roman Catholics and it does have Isaiah 66:22-24 and reads:
"For as the new heavens and the new earth, which I will make, shall remain before me, says the LORD; so shall your descendants and your name remain. From new moon to new moon, and from sabbath to sabbath, all flesh shall come to worship before me, says the LORD." Isaiah 66:22-23.