This is where most of your false doctrine originates. You cannot find any scripture that will substantiate this claim.
"Now when He rose early on the first day of the week, He appeared first to Mary Magdalene, out of whom He had cast seven demons." (Mark 16:9)
Mark 16 is pretty clear on the subject, unless you are predisposed by your theology to htink otherwise.
But just in case you do not believe the plain words of this text of Scripture, let's look at another:
Now on the first day of the week, very early in the morning, they, and certain other women with them, came to the tomb bringing the spices which they had prepared. ... He is not here, but is risen! Remember how He spoke to you when He was still in Galilee, saying, 'The Son of Man must be delivered into the hands of sinful men, and be crucified, and the third day rise again.' And they remembered His words. ...Without twisting the plain words of Luke, we see that on the first day of the week (lit. "the first of the sabbaths") the women arrived at the newly empty tomb. The "two men in shining garments" they encounter remind them of Jesus' owns words that He would rise from the dead "on the third day" following His crucifixion. Later in that same first day of the week (v. 13), two of the disciples have an encounter with Jesus and they recall the story of the crucifixion, and how that very day was "the third day" (v. 21) since these things surrounding the crucifixion happened.Now behold, two of them were traveling that same day to a village called Emmaus, which was seven miles from Jerusalem. And they talked together of all these things which had happened. So it was, while they conversed and reasoned, that Jesus Himself drew near and went with them. ... But we were hoping that it was He who was going to redeem Israel. Indeed, besides all this, today is the third day since these things happened,. Yes, and certain women of our company, who arrived at the tomb early, astonished us. (Luke 24:1,6-8,13-15,21,22)
The plain reading of this text is that Jesus rose on "the third day", which happened to be the first day of the week as recorded in Luke.
There is no way to twist out of that conclusion.
And so because of these facts the universal church from the days of the apostles onward has celebrated and worshipped the triune God on the first day of the week, according to the Scriptures, not according to the shadows of the Jews.
"Now when he rose, early on the first day of the week he appeared first to Mary Magdalene, out of whom He had cast seven demons." [Mark 16:9]
There is no punctuation in the original Greek....remember?
Now on the first day of the week, very early in the morning, they, and certain other women with them, came to the tomb bringing the spices which they had prepared. ... He is not here, but is risen! Remember how He spoke to you when He was still in Galilee, saying, 'The Son of Man must be delivered into the hands of sinful men, and be crucified, and the third day rise again.' And they remembered His words. ...
Where does this verse say he resurrected on the first day of the week? All it says is that he is not there!
Now behold, two of them were traveling that same day to a village called Emmaus, which was seven miles from Jerusalem. And they talked together of all these things which had happened. So it was, while they conversed and reasoned, that Jesus Himself drew near and went with them. ... But we were hoping that it was He who was going to redeem Israel. Indeed, besides all this, today is the third day since these things happened,. Yes, and certain women of our company, who arrived at the tomb early, astonished us. (Luke 24:1,6-8,13-15,21,22)
Two men are traveling on Sunday.....indisputable! The Greek word for "since" used here actually means "away from" which is closer to the English "after". Translators erred because they chose to make this verse less cumbersome in the English. Instead of saying "But surely also together with all these things, it brings a third day away from which all these thing occurred." They more properly should have said:
Today is after the third day since these things were done. In fact, the Syriac New Testament from the Peshitto Version says, "And lo, three days have passed since all these things have occurred."
And so because of these facts the universal church from the days of the apostles onward has celebrated and worshiped the triune God on the first day of the week, according to the Scriptures, not according to the shadows of the Jews
You are correct in that the Catholic Church has established it's Sabbath as Sunday, but where you go wrong is by saying it is scripturally factual. It is false doctrine and is easily shown to be so.