Exodus 29:35–37

In these closing verses of the ordination rite, God commands a seven-day consecration of Aaron and his sons, during which a bull is sacrificed each day as a sin offering to purify and anoint the altar itself. The climax of the passage is a startling declaration: once sanctified, the altar becomes "most holy," communicating holiness to whatever it touches. These verses reveal that mediation between God and humanity requires both protracted ritual purification and the ongoing power of atoning sacrifice.

Verse 35 — "You shall consecrate them seven days"

The Hebrew verb translated "consecrate" is millē' yādam — literally "to fill their hands." This idiom for priestly ordination likely refers to the literal filling of the priest's hands with portions of sacrifice (cf. v. 24), but it carries the deeper sense of being entrusted with a vocation, laden with sacred responsibility. The repetition of "according to all that I have commanded you" underscores total obedience: no part of the rite may be abbreviated or substituted. The seven-day duration is not incidental. In the Hebrew symbolic world, seven signals completion and cosmic fullness — God rested on the seventh day, sealing creation (Gen 2:2). A seven-day consecration thus mirrors the original creative act; the priesthood is not an administrative role but a new creation, a reordering of human beings toward God.

Verse 36 — The Daily Sin Offering and the Anointing of the Altar

Each of the seven days requires a fresh bull as a ḥaṭṭā't (sin/purification offering). This is striking: the sin offering is not offered once for the priests, but every single day of the week. The Septuagint renders "cleanse" (ḥiṭṭē't) with a term related to purification from defilement, reinforcing that the altar itself is susceptible to impurity — not because it is morally guilty, but because it exists in a world contaminated by sin and must be shielded from that contamination before it can function as a site of divine-human encounter. After cleansing, the altar is anointed with oil, the same gesture used for kings and prophets. Anointing in the Hebrew Bible consecrates persons and objects to a new mode of existence oriented entirely toward God. The altar is therefore not merely a piece of furniture; it becomes a participant in the sacred order.

Verse 37 — "The Altar Shall Be Most Holy; Whatever Touches It Shall Be Holy"

This verse contains one of the most theologically charged declarations in all of Exodus. The altar attains the status of qōdeš qŏdāšîm — "holy of holies" — the same phrase used for the inner sanctuary and for the most solemn class of offerings. This is holiness of the highest degree, belonging properly to God alone and communicated only by deliberate divine act. The final clause — "whatever touches the altar shall be holy" — functions almost as a law of contagion in reverse: rather than impurity spreading outward and contaminating the sacred, here holiness radiates outward from the altar and hallows whatever makes contact. This reflects what scholars call "positive holiness contagion," rare in the Levitical system, which is usually preoccupied with contamination moving in the other direction.

Catholic tradition identifies several layers of meaning that uniquely illuminate this passage.

On the Altar as Most Holy: The Second Vatican Council's Sacrosanctum Concilium (§7) affirms that Christ is present in the Eucharistic sacrifice above all under the Eucharistic species. The Catholic altar, like its Mosaic prototype, is not neutral space — it is the privileged locus of Christ's sacrificial presence. The General Instruction of the Roman Missal (§298) accordingly calls the altar "the center of thanksgiving that the Eucharist accomplishes" and requires that it be treated with singular reverence. The practice of consecrating altars with the relics of martyrs (GIRM §302) is a living extension of this Exodus theology: the altar's holiness is sealed by the blood of witnesses, just as the Mosaic altar was sealed by the blood of sacrifice.

On the Sevenfold Purification: St. Cyril of Alexandria saw in the seven days of priestly consecration a type of the soul's progressive sanctification through the sacraments and moral growth. The Catechism of the Catholic Church (§1589) echoes Hebrews in affirming that ordained ministers, unlike the Levitical priests, share in the one priesthood of Christ — a priesthood that requires no repetition, because Christ, our High Priest, lives always to intercede (Heb 7:25). Yet even in the New Covenant, formation for priestly ministry is characteristically extended and gradual — seminary formation, diaconal ordination, priestly formation — a structural echo of the Mosaic pattern.

On "Whatever Touches the Altar Shall Be Holy": St. Thomas Aquinas, in Summa Theologiae III, q.83, draws on this verse when discussing the sanctifying power of the Eucharistic action: the sacrifice of the Mass communicates the holiness of Christ's one sacrifice to those who approach it worthily. This principle also grounds the Catholic theological tradition of sacramental ex opere operato efficacy — holiness flows from the sacred act itself, not solely from the subjective disposition of the minister.

These verses speak to contemporary Catholics in at least three concrete ways. First, the seven-day purification challenges our culture of instant transformation: holiness is not a single experience but a sustained process of daily return to God, daily offering of oneself, daily anointing with grace. The Catholic practice of frequent Confession — not just once but regularly — resonates with the daily sin offering: we are not purified once and done, but must continually bring our moral contamination to the altar of God's mercy. Second, the declaration that "the altar shall be most holy" invites a recovery of Eucharistic reverence. Many Catholics enter the sanctuary with the same casualness one might bring to a community hall. This passage insists that the altar is the threshold of the Most Holy — an invitation to renewed liturgical reverence: genuflection, silence, attentive presence. Third, "whatever touches the altar shall be holy" is a missionary promise: every person who draws near to the Eucharistic sacrifice is offered a real transformation, not merely a symbolic one. Catholics are called to bring others — the lapsed, the searching, the burdened — into contact with the altar, trusting that the holiness is real and active.