G-d also reveals to Moses how to make the priestly garments and describes the seven day ritual to invest Aaron (Cohen Gadol) and his sons Nadav, Avihu, Elazar and Itamar (Cohanim) as priests. …

During his forty-day vigil in the mountain, G-d provides Moses with detailed instructions about how to build the tabernacle, the Mishkan, and its furnishing,

G-d has just given the Ten Commandments on mount Sinai. Moshé informs the people of numerous ethical and ritual laws and seals the covenant between the Children of Israel and G-d.