Is it obligatory to wash the hair in front of the ears (al-'idhar) with the face or separately?

The 'idhar' (sideburn) is part of the face. It is washed by pouring water over it until it reaches the skin beneath, if it is thin enough for the skin to be seen through it. Whether it is washed alone or with the rest of the face, the important thing is to wash this area. This washing is easy for one who avoids obsessive thoughts (waswas).