A.T. Robertson Commentary Luke 23:56

"And they returned, and prepared spices and ointments. And on the sabbath they rested according to the commandment." — Luke 23:56 (ASV)

On the sabbath they rested (το σαββατον ησυχασαν). They returned and prepared spices before the sabbath began. Then they rested all during the sabbath (accusative of extent of time, το σαββατον).