Exodus 20:8–11 King James Version
8 Remember the sabbath day, to keep it holy. 9 Six days shalt thou labour, and do all thy work: 10 But the seventh day is the sabbath of the LORD thy God: in it thou shalt not do any work, thou, nor thy son, nor thy daughter, thy manservant, nor thy maidservant, nor thy cattle, nor thy stranger that is within thy gates: 11 For in six days the LORD made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the LORD blessed the sabbath day, and hallowed it.
Romans 14:4–6 King James Version
4 Who art thou that judgest another man’s servant? to his own master he standeth or falleth. Yea, he shall be holden up: for God is able to make him stand. 5 One man esteemeth one day above another: another esteemeth every day alike. Let every man be fully persuaded in his own mind. 6 He that regardeth the day, regardeth it unto the Lord; and he that regardeth not the day, to the Lord he doth not regard it. He that eateth, eateth to the Lord, for he giveth God thanks; and he that eateth not, to the Lord he eateth not, and giveth God thanks.