Is there any biblical or theological basis for believing that Adam and Eve themselves observed a Sabbath prior to the Fall?

In Genesis 2:2–3, God rests on the seventh day and blesses and sanctifies it. However, the explicit command to observe the Sabbath does not appear until Exodus 16 and is formally given in the Decalogue in Exodus 20:8–11. Does Genesis imply that the sanctification of the seventh day functioned as an ordinance for humanity from creation? Or is the Sabbath understood in Christian theology to have been instituted later, particularly within the Mosaic covenant?