"In the law given from Sinai, God recognized the week, and the facts upon which it is based. After giving the command, “Remember the Sabbath day to keep it holy,” and specifying what shall be done on the six days, and what shall not be done on the seventh, he states the reason for thus observing the week, by pointing back to his own example: “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.” [ Exodus 20:8-11 .] This reason appears beautiful and forcible when we understand the days of creation to be literal. The first six days of each week are given to man for labor, because God employed the same period of the first week in the work of creation. On the seventh day man is to refrain from labor, in commemoration of the Creator's rest. CE 190.2"
"Remember the sabbath day, to keep it holy. Six days shalt thou labour, and do all thy work: 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: 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."
Ellen White directly references Exodus 20:8-11 in this passage.