Tetzaveh - Rishon
A Little Background Information...
There is a difference of opinion as to when parshas Terumah and Tetzaveh were given. Many commentators feel that these laws were commanded after the incident of the Golden Calf in parshas Ki Sisa (see Rashi on 31:18). Many hints to this can be seen in the text. For example, in 26:30 (in last week's parsha), G-d tells Moshe to set up the Mishkan the way he was shown on the mountain, suggesting that these parshas were said after Moshe descended from his first trip up the mountain.
So why tell you this now? Because this parsha treats Aharon and his sons as the kohanim (priests) and we are following the opinion that this is a job they don't actually receive until after the incident with the Golden Calf. (It is not uncommon for the Torah to go out of chronological order. For example, the Book of Bereishis frequently reports people's deaths before they actually occur, simply because the Torah is done talking about them - see Talmud Pesachim 6b.)
So, where were we? Oh, yes...
G-d told Moshe to have pure olive oil made for the Menorah. Aharon and his sons would be responsible for setting up the Menorah every evening, so that it would burn all night.
Special garments were to be made for Aharon to wear while performing the service. The clothes are an indispensable part of his consecration. They include a breastplate, an ephod (kind of an apron), a robe, a tunic, a turban and a belt, which will be described in greater detail.
The ephod was to be made of gold thread, plus blue and crimson wool, woven in a pattern. There would be attached shoulder straps and a waistband. On the shoulders, they were to place two gems engraved with the names of Yaakov's sons, six on each. This way, Aharon would carry a constant reminder of the Jews before G-d.