Aliya Summary: The Levites are appointed to serve in the Tabernacle, guard its vessels and assist the priests with their Tabernacle duties. This honor originally belonged to the Israelite firstborns, who were “acquired” by G‑d when He spared them during the Plague of the Firstborn. This privilege was taken away from them when they participated in the sin of the Golden Calf — and given to the Levites.
“These are the names of the sons of Aharon, the B’chor (firstborn) Nadav…” The regular reading of the pasuk, based on the Taamei HaMikra (the Torah notes) indicates that Nadav is being identified as Aharon’s B’chor. But there is a vertical line which separates between B’chor and Nadav, suggesting that it is Aharon the B’chor; Nadav, having died without children is not really a B’chor at this point. (Since the children of a deceased B’chor get their father’s double portion, had Nadav had children he would retain the title of B’chor.)