Eze 20:12 – Moreover also I gave them my sabbaths, to be a sign between me and them, that they might know that I am the LORD that sanctify them.
Acts 20:7 – And upon the first day of the week, when the disciples came together to break bread, Paul preached unto them
1 Cor 16:2 – Upon the first day of the week let every one of you lay by him in store, as God hath prospered him, that there be no gatherings when I come.
Col 2:16-17 – Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath days: Which are a shadow of things to come; but the body is of Christ.
Heb 10:1 – For the law having a shadow of good things to come, and not the very image of the things, can never with those sacrifices which they offered year by year continually make the comers thereunto perfect.
The Bible teaches that the OT sabbath pointed to what was to come, Christ who fulfilled the law. Christ rose on a Sunday, the Holy Spirit was poured out at Pentecost on a Sunday, and so on.
The Saturday Sabbath was completed upon the finished work of Christ in His death and resurrection. Notice the original text in Matt 28:1 -” In the end of the sabbath (Greek word ‘sabbaton’), as it began to dawn toward the first day of the week (same word ‘sabbaton’), came Mary Magdalene and the other Mary to see the sepulchre.” The term “first day of the week” is the same plural Greek word as the one used for “sabbath”. This verse could be translated – “In the end of the era of sabbaths (Saturday’s), as it began to dawn toward the new era of sabbaths (Sunday’s) . . .” See also Acts 20:7 and 1 Cor 16:1-2 which indicate preaching and giving were done when the believers gathered on Sunday to worship.