Joshua 22:17:

Is the iniquity of Peor too little for us, from which we are not cleansed until this day, although there was a plague in the congregation of the LORD,

Notes on Joshua 22:17:

This is yet another passage that links sin (iniquity) and sickness (a plague).  In Joshua’s day, they were “not cleansed until this day,” but it our day, you are cleansed by Jesus’ blood, and therefore the punishment for sin – sickness – does NOT belong to you.

See also:

Sickness as Chastening and Judgment in the Old Testament