The Catholic Cardinal Gibbons, in Faith of Our Fathers, pg. 111, said, "You may read the Bible from Genesis to Revelation, and you will not find a single line authorizing the sanctification of Sunday. The Scriptures enforce the religious observance of Saturday, a day which we (The Roman Catholic Church) never sanctify.
The Catholic Mirror (a publication by Cardinal Gibbons) Sept. 2, 1893- "...the Redeemer, during His mortal life, never kept any other day than Saturday."
The Catholic Mirror Sept. 9, 1893- "Nor can we imagine any one foolhardy enough to question the identity of Saturday with the Sabbath or seventh day, seeing that the people of Israel have been keeping the Saturday from the giving of the Law, A.M., 2514 to A.D. 1893 (to the present day)..."
The Catholic Mirror Sept.9, 1893- "We deem it necessary to be perfectly clear on this point....The Bible- the Old Testament- confirmed by the living tradition of weekly practice for 3383 years by the chosen people of God, teaches, then, with absolute certainty, that God had, Himself, named the day "to be kept holy to Him"- that the day was Saturday, and that any violation of that command was punishable with death."
Peter Geiermann, C.S.S.R., The Converts Catechism of Catholic Doctrine Third Edition"1). Question: Which is the Sabbath day? "Answer: Saturday is the Sabbath day. 2). "Question: Why do we observe Sunday instead of Saturday?"Answer. "We observe Sunday instead of Saturday because the Catholic Church in the Council of Laodicea, transferred the solemnity from Saturday to Sunday."
http://www.truthontheweb.org/notes.htm
Note: The Sabbath was at the beginning at creation. God rested ONE day not because he was tired. But because he wanted to commune with US.
Isaiah 40:28 Hast thou not known? hast thou not heard, that the everlasting God, the Lord, the Creator of the ends of the earth, fainteth not, neither is he weary?
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Which day is the Sabbath?
"The seventh day is the sabbath of the Lord thy God." Exodus 20:10. "And when the sabbath was past, ...very early in the morning the first day of the week, they came unto the sepulchre." Mark 16:1,2.
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Note: The Saints will keep the Sabbath in heaven.
Isa 66:22 For as the new heavens and the new earth, which I will make, shall remain before me, saith the LORD, so shall your seed and your name remain.
Isa 66:23 And it shall come to pass, [that] from one new moon to another, and from one sabbath to another, shall all flesh come to worship before me, saith the LORD.