Rn — the true name
The spell-bound essence of a being
Rn — the true name. To possess a being's rn is to possess heka over it; the gods' secret names are the high-stakes object of magical narrative (most famously, Isis's acquisition of Re's name in the Turin Magical Papyrus). Conversely, the writing and pronouncing of one's own rn is the technique by which the deceased asserts existence and protection in the underworld. Located here at the crown rather than within the body, since the rn is what binds the entire person and is the locus on which all heka-operations take a grip.
Point 4 of 5 in Egyptian Heka — Words of Power
Cross-tradition overlaps
No overlapping points are registered for this point.
Sources
The Legend of Isis and Re (Turin Magical Papyrus 1993) (primary_canonical)
The Legend of Isis and Re in Papyrus Turin 1993 turns on Isis's healing of Re's hidden name and the consequent disclosure of that name; this central name-revelation episode is the specific textual locus for the heka of knowing a being's ren.
Book of the Dead, spell 25 (Causing N to remember his name) (primary_canonical)
Faulkner's Ancient Egyptian Book of the Dead, Spell 25, 'The spell for giving N his name,' concerns the deceased's ability to state and retain the name by which he is recognised in the otherworld; the spell is a direct funerary complement to the Isis–Re name narrative.