Job 18:15 (ESV)

15 In his tent dwells that which is none of his; sulfur is scattered over his habitation.

Possibly, the home of a diseased person was set on fire in order to prevent the disease from spreading. But above all, fire and burning sulfur were signs of God’s curse over sin (Genesis 9:24; Deuteronomy 29:23

These words of Bildad would have reminded Job of the destruction of his own sheep and servants through fire (Job 1:16).