The Gospel tells a story about the Pharisees accusing the Apostles of violating the Sabbath by rubbing the husks off of handfuls of grain. Chapter Twenty of Exodus speaks of God giving the Ten Commandment to Moses, and the Jews rightly saw the commandment about keeping the Sabbath holy to mean they were to abstain from manual labor.
But, as Jesus pointed out, “the Sabbath was made for man, not man for the Sabbath.” We see this spelled out in Chapter Twenty-three of Exodus where we read God’s reason for imposing the Sabbath on landowners. 10. “For six days you may do your work, but on the seventh day you must rest, that your ox and your ass may also have rest, and that the son or our maidservant and the alien may be refreshed.”
So, those of us who get plenty of rest the other six days of the week need not feel obligated to be idle on Sundays.
What is more, with Jesus saying that church rules are made to help, not hinder, we should feel free to skip Mass in order to look after a sick person.