After the description of the priest’s garments, the consecration ritual for the priests is provided (Ex. 29). The opening verses set out the supplies that will be used in ceremonies described later in the chapter (Ex. 29:1-3). Next Aaron and his sons were to be washed, clothed, and anointed (Ex. 29:4-9). The washing indicates the need for cleansing before being invested with “holy garments” (Ex. 28:2). The garments are listed (calling to mind briefly the significance of each raised by the previous chapter). The anointing with oil is the symbol of the ordination.
A series of sacrifices follow the washing, investing, and anointing. The first offering was to be a sin/purification offering (Ex. 29:10-14).* This sacrifice was offered to atone for sins committed when one strayed from the commandments of God.** Next Moses was to offer a ram as a burn offering (Ex. 29:15-18). The burnt offering probably symbolized the entire consecration of the one who offered it since this sacrifice was entirely burned. The second ram, called the ram of ordination, was killed and it was used in two stages. First, its blood was applied to Aaron, his sons, and their garments (Ex 29:19-21). This sacrifice was to make the priests and their garments holy. Next this ram along with some bread was used as a wave offering. Wave offerings are often (though not always) connected with peace offerings, as is the case here (Ex. 29:28). There may be a progression here from the sin offering that provided purification from sin, to the burnt offering which symbolized entire consecration, to the ram of ordination which was used, along with the ordination, as part of a peace offering which may symbolize fellowship with God.
Exodus 29:29-30 turns the emphasis to the garments worn by the priests and it raises the matter of succession. Then follows a description of a meal from the ordination ram (Ex. 29:31-34). This seems to indicate fellowship now made possible through atonement. This is followed by instructions for a seven day series of sin offerings and consecrations of the altar in connection with the ordination (Ex. 29:35-37).
The chapter closes by moving from the ordination to the work that the priests were ordained to do. They were to offer morning and evening sacrifices (Ex. 29:38-42). The great significance of the priesthood , and the tabernacle, and the sacrifices are found in the last verses of the chapter—Exodus 29:42-46. The tabernacle was the place where God would meet with his people. It was a holy place were this meeting could take place. Furthermore, not only would God meet with his people at the tabernacle, he would dwell among them, and he would be their God. And, in a theme that runs throughout Exodus, they would know that he is the Lord God.
*Milgrom argues for the translation “purification offering” on the grounds that (1) it is sometimes offered in cases other than to atone for sins (Lev. 8:15; 12:6; Num. 6:10) and (2) the term חַטָּאת is derived from the piel which means “to cleanse, expurgate, decontaminate.” Jacob Milgrom, “Sin-Offering or Purification-Offering?” Vetus Testamentum 21 (April 1971): 237. Averbeck accepts Milgrom’s reasoning but offers the caution, “it should not be taken to mean that the sin offering only applied to issues of physical (amoral) uncleanness. According to Leviticus 4:2, for example, it applied to ‘any of the Lord’s commandments.’” “Sacrifices and Offerings,” Dictionary of the Old Testament: Pentateuch, eds. T. Desmond Alexander and David W. Baker (Downers Grove: InterVarsity, 2003), 718.
**Roy Beacham argues that שְׁגָגָה or שׁגה, which are usually translated “unintentionally” or “sins unintentionally,” should simply be translated “in error” or “to go astray.” He argues that if the sin is unintentional there needs to be a qualifying phrase that makes that point. In arguing for this position Beacham notes it is impossible to commit the sin noted in Lev. 5:1 unintentionally. Texts outside the Pentateuch also confirm that sins designated as שְׁגָגָה or שׁגה are known sins (Psa. 119:118; Pro. 5:23; 19:27; 28:10; 1 Sam. 26:21).