The children of Israel are commanded to bring pure olive oil for the ner tamid "a constantly burning light," above the sanctuary. (27:20-21). Aaron and his sons, Nadab, Abihu, Eleazar, and Ithamar, are chosen to serve as priests. (28:1). God instructs Moses to make special clothes for the priests. (28:2-43). Aaron and his sons are ordained in a seven-day ceremony (29:1-29:46). Aaron is commanded to burn incense on an acacia altar every morning and evening. (30:1-10).Â