What makes it quietly extraordinary is not its size but what it carries: an early medieval inscription arranged across the four cantons of a Latin cross, its letters worn but still legible, asking God's blessing on a soul named Sanctan.

The slab bears a Latin cross with expanded triangular terminals, a form commonly found on early Irish ecclesiastical stonework, where the arms of the cross flare outward at each tip rather than ending in a plain cut. Running clockwise from the top left, the inscription reads, in expanded form, BENDACHT DIE FOR ANIM SANCTAN, meaning roughly "a blessing of God on the soul of Sanctan." The formula is a standard one in early Irish memorial epigraphy, but its survival here, incorporated into the fabric of the altar at Teaghlach Éinne, the early monastic site associated with Saint Éinne (or Enda), the sixth-century founder credited with establishing one of Ireland's earliest monasteries, gives it particular weight. The scholar Máire Mac Néill published a reading of the inscription in 1938, and it has been discussed in subsequent surveys of the site's stonework.

The slab is not displayed in isolation but built directly into the altar, which means a visitor to Teaghlach Éinne will need to look carefully at the altar's south face to find it. The carving is modest and the stone weathered, so taking a moment to let the eye adjust to the surface is worthwhile.