Wiping over bandages, splints, or casts

"I broke one of my forearms and I asked the Prophet about that. He told me to wipe over the bandages." (Maudu') Another chain with similar meaning.  

انْكَسَرَتْ إِحْدَى زَنْدَىَّ فَسَأَلْتُ النَّبِيَّ ﷺ فَأَمَرَنِي أَنْ أَمْسَحَ عَلَى الْجَبَائِرِ