Parshat Bamidbar reflects two different aspects of the selection of the Levi’im. The first selection, described in chapter 1, arises from the sanctity of the tribe of Levi as a whole, as it was sanctified for God's service in the wake of the sin of the golden calf. According to the other perspective, as reflected in chapter 3, the source of the holiness of the Levi’im is actually the prior selection of the firstborn; the Levi’im are simply the replacement for the firstborn. Through a close analysis of the text we can understand the nature of the differences in these perspectives, and understand the unique role of the Levi’im.