In Deuteronomy 33:8-10 three main functions are ascribed to Levi, who here respresents the Israelite priesthood:
It is probably significant that the giving of oracles or revelations and instruction in the Law (Torah) precede altar service. A different order appears in the summary of priestly functions in 1 Sam.2:28: "to go up to My altar, to burn incence, to wear an ephod before Me"; but there, too, there is probably a reference to the discerning of the divine will. The ephod is described sometimes as a priestly vestment (1 Sam.2:18; 2 Sam.6:14) and sometimes as a cultic  object (Judg.8:27). It also appears to have had some association with the giving of oracles (1 Sam.23:9-12). We cannot be sure of its precise character, or, indeed, whether there was only one kind of ephod; but since in the account of the High Priest's cestments (Ex.28) we are told that there was attached a "breastplate" which was in effect a pouch to hold the Urim & Thummim (the oracular dice), the ephod which was a vestment was not necessarily distint from the ephod which was associated with the giving of oracles .
- 1. "Give to Levi thy Thummim, and thy Urim to thy godly ones" means that the priest ascertain the divine will by the manipulation of the sacred dice or lottery, the Urim & Thummim;
- 2. "They shall teach Jacob thy ordinances, and Israel thy law" refers to the teaching office of the priesthood; and
- 3. "They shall put uncense before Thee, and whole burnt offerings upon Thy altar" describes the priestly service of Elohim (God) at the altar.
The teaching office of the priesthood was probably of far greater importance than is commonly realised; and it was certainly wider in scope than is suggested by the English words "ordinances" and "law" in Deut.33:10. It involved not only giving decisions on moot points and guidance about ritual usage, but general instruction about the will of Yahweh. Although the Hebrew word torah (law) could be used of the revelation imparted through the prophet (Is.1:10), it was used with peculioar appropriateness of priestly instruction. In Jer.18:18 the torah of the priest is bracketed with the counsel of the wise man and the word of the prophet. Priests are denounced because they make their teaching office a source of profit (Mic.3:11; cp. Mal.2:7f).
The burning of incense and the offering of sacrifice are linked together because of their association with the altar. In sacrifice, the special task of the priest was not the actual slaughtering of the victim (though he might, in some circumstances, do this), but the sprinkling of the blood and the laying on the altar of what was given to Yahweh. The function came to be of special importance in later times, when the giving of oracles by priests had ceased and their teaching was less prominent. In the early period, though sacrifice was one of the functions of the priests, it was not restricted to them. Sacrifice was offered by Gideon (Judg.6:25ff) and by Samson's father, manoah (Judg.13:16-23).
The Levites had a special relationship to the priestly office and the service of the sanctuary. In Deuteronomy, though the position is not entirely clear, priests and Levites seem to be equated (e.g. Dt.18:1-5). In the alleged Priestly Source (P). the specifically priestly functions are reserved for those Levites who are descended from Aaron, whereas the remaining Levites are to be responsible for other forms of service in the sanctuary (Num.18:1-7). An even narrow limitation of the service of the altar is rpescribed in the book of Ezekiel, where full priestly status is reserved for the Zadokites (Ezek.40:46). But in the period with which we are at present concerned, not all priests were Levites. Though he was an Ephraimite (1 Sam.1:1), Samuel was a priest at the sanctuary at Shiloh; and after it was destroyed he continued to perform priestly functions in different parts of the country. David who was of the tribe of Judah, had sons who were priests (2 Sam.8:18). Judges 17 tells of an Ephraimite named Micah who established a private sanctuary and installed one of his sons as priest (v.5) ; but when a Levite turned up, Micah immediately took the opportunity of employing him (vv.7-13). It appears then, that at least until the early period of thre monarchy, priesthood was not confined to the Levites, though Levitical priests were preferred. At the same time it is not to be understood that this state of affairs reflected the divine will for it is quite clear that the period of the Judges was a time of major apostacy. Though the exercise of the priesthood is recorded as having been performed by those outside of the tribe of Levi during this period, it is nowhere commended, and is certainly out of harmony with Mosaic Law.
The biblical traditions about the origins and early history of the Levites are difficult to interpret. On the one hand, they are represented as having lost their tribal cohesion and become dispersed in Israel (Gen.49:5-7) because of an atrocity committed in pre-Mosaic times. On the other hand, the priestly office is said to have been assigned to them because of their attitude to idolatry and apostacy (Ex.32:26-29; Dt.33:8-10). The suggestion has been made that there was a non-priestly tribe of Levi, which was distinct from the Levites who specialised in cultic functions, but which in effect ceased to exist as a recognisable entity. Where the evidence is fragmentary and obscure, it is unwise to be dogmatic; but it seems to be neither impossible nor improbable that there was in fact one tribe of Levi, which, at an early period, came to specialise in cultic functions, and later assimilated other elements who shared in these functions at various sanctuaries.
The establishment of the monarchy was itself an important religious development and the choice of the royal city, and the choice of the royal sanctuary, had far reaching effects on national life and religious practice. These developments also had both immediate and long-term consequences for the priesthood. After the Philistines had destroyed Shiloh and its temple, an important community of priests was presided over at Nob by Ahimelech, a descendant of Eli; but it was almost completely wiped out by Saul, because Ahimelech had helped David (1 Sam.21-22). The sole survivor, Abiathar, joined David's band of outlaws and served as his priest. After the capture of Jerusalem, another priest, Zadok, appears in David's entourage. The priests who were attached to the court and the royaö sanctuary would naturally have a special prestige and authority. At the beginning of Solomon's reign, Abiathar fell from favour and was dismissed. Thereafter the Zadokite priests, like the Temple at which they served, were to execise for centuries a rôle of increasing importance.
 The words 'cult' and 'cultic' are not used here in the modern vernacular sense of a 'dangerous religious group' but in the academic sense of a 'specific system of religious worship' irrespective of whether that system is regarded as positive or negative.
 See Benjamin: The Heart of an Israelite Tribe Yesterday and Today