Isaiah 56:2

Blessed is the man that doeth this, weak and mortal as he is in his own person, and the son of man, offspring of sinful and mortal parents, that layeth hold on it, namely, in observing the covenant made upon Sinai, that keepeth the Sabbath from polluting it, since it was the day when the blessed communion between God and His people was stressed most strongly, and keepeth his hand from doing any evil. In urging the keeping of the Sabbath and the observing of the demands of righteousness the prophet is not insisting upon a mere outward mechanical observance of the Law, but desires a return to the ancient covenant faithfulness.