"IN THE Catholic Christian Instructed, chapter 23, we find the following questions and answers:
Question: What warrant have you for keeping the Sunday preferable to the ancient Sabbath, which was the Saturday?
Answer: We have for it the authority of the Catholic Church, and apostolic tradition.
Q.: Does the Scripture anywhere command the Sunday to be kept for the Sabbath?
A.: The Scripture commands us to hear the church,...but the Scripture does not in particular mention this change of the Sabbath. St. John speaks of the Lord’s day (Revelation 1:10), but he does not tell us what day of the week this was, much less does he tell us that this day was to take the place of the Sabbath ordained in the 
commandments.
St. Luke also speaks of the disciples meeting together to break bread on the first day of the week. Acts 20:7.
And St. Paul (1 Corinthians 16:2) orders that on the first day of the week the Corinthians should lay by in store what they designed to bestow in charity on the faithful in Judea; but neither the one nor the other tell us that this first day of the week was to be henceforward the day of worship, and the Christian Sabbath; so that truly the best authority we have for this is the testimony and ordinance of the church.
And therefore those who pretend to be such religious observers of the Sunday whilst they take no notice of other festivals ordained by the same church-authority, show that they act more by humor, than by reason and religion; since Sundays and holydays all stand upon the same foundation, viz., the ordinance of the church.
This is plain language, but no Sunday-keeping Protestant can deny it." E.J. Waggoner