Q: If a person touches something napak, then his hands become napak. Now this person forgets and touches his phone, does his phone become napak?
A: If any traces of impurity got on to the phone, the phone will become napaak and will have to be washed.
And Allah Ta’ala (الله تعالى) knows best.
نام أو مشى على نجاسة إن ظهر عينها تنجس وإلا لا ( رد المحتار 1/346)
Checked & Approved: