Q: I have been reading a number of canonical texts and older legislation regarding the consecration of altars. I saw in some of these writings a passing reference to the practice of placing 3 grains of incense in the reliquary, along with the relics and parchment of authentication before it was sealed in wax.
Are you aware of the reason behind this practice of placing grains of incense with the relics?
==
A: I ran across something like this while I was writing my book New Church, New Altar. https://litpress.org/Products/6659/New-Church-New-Altar
I make a reference there to the 9th century Roman Ordo XLII with this summary:
“As the relics were brought forward, the schola sang a litany. The bishop offered a prayer, received the relics from a priest, and set them on the new altar. The bishop anointed the four corners of the aperture with chrism, inserted three particles of the consecrated Body of the Lord along with three grains of incense, and placed the relics into the same opening. Meanwhile, all sang the Revelation-inspired antiphon that has survived from the ninth century through the contemporary rite with only minor changes: ‘Beneath the altar of the Lord you have been placed: intercede for us through the one by whom you have been made worthy.’ The bishop offered another prayer and sealed the relics inside with the cement he had prepared.”
I don’t remember seeing an explanation, but it probably symbolizes what burned incense may symbolize: a recognition of the holiness of the object it honors.