Leprosy, or at least a severe cutaneous disease so called, was common
in ancient Ireland; and there are numerous stories, some of them
extremely disagreeable, that tell how the saints associated with its
victims as an act of self-abasement. We have already seen how Patrick
was said to have kept a leper. Brigit also healed lepers by washing
(LL, 1620), and Ruadan cleansed lepers with the water of a spring
that he opened miraculously (VSH, ii, 249). Contrariwise, Munnu never
washed except at Easter after contracting leprosy (VSH, ii, 237).
The miraculous opening of a spring is a common incident in Irish
hagiography; we have already seen an example, in the annotations to
incident I.
Whitley Stokes points out (LL, note _ad loc._) that the "three waves"
poured over the lepers are suggested by the triple immersion in
baptism.