I am not sure about the Roman liturgy. It is very common among the Eastern and Oriental Churches to bless anyone who enters into the “Holy of Holies” / Sanctuary /etc. that is not at least ordained to a Minor Order.
This is an example of the rite for the Admission of an Altar Boy to the Altar from a West Syriac perspective:
ADMITTING ALTAR BOYS TO MADH’BAHA
Hearken, Lord in Thy mercy And hear our prayers and pleas Accept these supplications
And be pleased in them, O Lord!
Deacon: Barekmor. Stoumen Kalos.
Bishop: Let us all pray and beseech the Lord for grace and mercy.
People: O Merciful Lord, have mercy upon us and help us.
Bishop: Glory and Thanksgiving, praise and adoration, and exaltation unceasing, truly at all times and at all hours, may we ascribe unto Thee, O Lord!
Glory be to God, Father, Son and the Holy Spirit, who accepts those who repent, who forgives those who are fallen in sin, who makes just men out of sinners, and who wipes away the failings of those who repent and turn back to Thee. Lord, by Thy mercy, sanctify these Thy sons who have approached Thy presence to bear the joyful yoke of your service. Strengthen them to obey your commandments, for Thou alone art the good and merciful Lord. To Thee be glory and honor and worship at this time when your servants are received for this office, and at all times and seasons and hours, and all the days of our lives.
Thou compassionate and merciful Lord, it is Thy Will that all creation must be redeemed. Thou hast spread the wings of Thy mercy over everything. Thou art merciful towards everything. Lord, bless your servants who have turned and come to Thee for bearing Thy yoke joyfully on their shoulders, bowing their head and submitting themselves unto Thee. Lord, protect them, sanctify them and have mercy
upon them. They desire the blessed share of Thy dwelling place. Therefore, Lord, we pray unto Thee, by Thy mercy, remove all their transgressions; wipe away all their misdeeds, willful or otherwise. Give them the strength to offer themselves as a sacrifice in perfect holiness. Adorn them in holy life and in the fullness of love for Thee. Make them worthy of the wisdom of Thy prophets; make them worthy of the sanctity of your Apostles; make them worthy of the courage of your martyrs. Lord, join them to the company of Thy saints, with the fullness of virtue, which they may gain from all these. Lead them to the light, which is the fruit of the observance of your commandments. Give them the strength to trample upon all sinful thoughts, feelings, and events. Enable them to sever themselves form all harmful emotions. Protect them from the snares and oppositions of the devil. Save them from the temptations and deceits of evil men. Redeem them from all sorts of sins. May Thy right hand strengthen them, so that they may take on all enemies. May they come out victorious and glorify Thy Holy Name. May they glorify Thee in all things, activities and relationships, in sleep as in wakefulness. May they dedicate themselves and live for Thee. Nurture them to minister unto Thee at all times. May they become the instruments of Thy glory. As we dedicate them before Thee, may we and their family members receive blessings from Thee. To Thee, we lift up glory and honor, praise and thanksgiving, now and always forever and ever.
Bishop: From God may we receive remission of debts and forgiveness of sins, in both worlds, forever and ever.
The Bishop will lay hands on the head of the individual and pray:
In the Name of the Father, Son and the Holy Spirit, One in Essence … (Baptismal Name)
Is blessed, set apart, and sealed for serving in the Holy Madhbaha.
Bashmo - dabo, O, dabro …
Hymn chanted during the blessing of surplice and putting on of surplice:
For glory and honor of
Trinity, one in essence
Lord, make for peace in Thy Church And advancement for ever
The Bishop will bring acolytes into the altar for the very first time and the following hymn is chanted:
Blessed are those servants good
Whom their Lord shall find
Waking working when He comes to His vineyard good Girding up His – loins He serves them all
They who worked with – Him from morn till eve
God the Father makes them sit and the Son serves them Lo the Holy Paraclete plaits them victor’s crown Halleluiah – setting on their heads