Is wiping over a dressing applied without prior ritual purity permissible?
Chapter on Tayammum
Al-Mughni
Book of Purification
Primary text
If a dressing is applied when the person is not in a state of ritual purity (Taharah), there is disagreement regarding the permissibility of wiping over it. If the ruling adopted is that wiping is not permissible in this circumstance, then Tayammum becomes obligatory for that area.
Supporting text
If the opposing view is adopted, the obligation is wiping. To resolve the difference of opinion, one may perform both wiping and Tayammum.