Some people believe that, since the Sabbath commandment isn't explicitly repeated in the New Testament, it is no longer binding.
The Sabbath commandment did not have to be repeated in the New Testament simply because the people to whom Jesus Christ and the apostles preached would not have imagined that it needed to be repeated.
The Scriptures that later would be called the Old Testament were their Bible, their guide for living (Romans 15:4). Paul described them as being "given by inspiration of God, and…profitable for doctrine, for reproof, for correction, for instruction in righteousness, that the man of God may be complete, thoroughly equipped for every good work" (2 Timothy 3:16, 17). The holy Scriptures clearly commanded them to keep the Sabbath, and the common people accepted that as God's inspired instruction.
Jesus Christ and the apostles lived and taught in a Sabbath-keeping society. Jesus' confrontations with the Pharisees were over how to observe the Sabbath, never over whether to observe it.
When the apostles took their message beyond the confines of Judea, Sabbath observance was well known in other parts of the Roman Empire. The Jewish historian Josephus, during the time of the New Testament Church, wrote,
"The multitude of mankind itself have had a great inclination for a long time to follow our religious observances; for there is not any city of the Grecians, nor any of the barbarians, nor any nation whatsoever, whither our custom of resting on the seventh day hath not come…As God himself pervades all the world, so hath our law passed through all the world also" (Against Apion, 2, 40).
The examples of Jesus and the apostles confirm that they believed in and obeyed all of the Ten Commandments. Throughout the book of Acts—written by Luke, a gentile—described in Leviticus 23 are mentioned quite routinely (Acts 13:14, 42, 44; 16:13; 17:2; 18:4, 21; 20:6, 16; 27:9). Whether to observe them simply wasn't a question.