Roamer_1 explained Acts 20 in his previous post.
But what I want to point out is this. IF the dissolution of the 4th commandment was taught by Christ and understood as such by his followers then it begs a couple of questions:
1. Why no controversy? The sabbaths are in the bible. They had been observed by Israelites for thousands of years. Surely there would have been an uproar and discussion among early Christians and persecution by Jews. By contrast look at the issue of circumcision...huge controversy that reverberates throughout scripture and it wasn't even one the ten big ones! Nah, it's clear that very early Christians kept the sabbath.
2. Look at traditional church history. The issue of whether to keep the biblical sabbaths wasn't officially decided until 360 AD (or thereabouts). It's exactly because there was no biblical precedent for it. Those verses you're going to point to are all latter day justification for abandoning it. There are just as many, if not more, new testament references to sabbath worship and observance.
While the old covenant instructed the Jews to observe the Sabbath, the new covenant contains no such instruction. What we find in the Scriptures instead is the practice of and commands relating to the assembling of the saints on the first day of the week.
Whether others had a custom of assembling for other purposes on that day or not is as irrelevant as the assembling of spectators at a Sunday Nascar race. :-) All we’re interested in is what Christ delivered to the saints through His apostles, and that’s the assembling on the day He was raised from the dead to commemorate His sacrifice, etc.
More than that, how does Yeshua 'add and remove' from Torah without being a false prophet? Necessarily, he can't have.