Is it permissible to describe a religious act as an innovation (bid‘ah) if its evidence is weak, such as wiping the face after supplication, wiping the neck during ablution, and Salatul Tasabih (the Witr prayer)?

It is permissible to apply the term bid‘ah (innovation) to an act whose evidence is weak according to those who believe it to be weak, and the matter remains subject to juristic discretion (ijtihad) as long as the dissenter relies on the hadith.

As an example of applying the term bid‘ah: Al-San‘ani described the practice of instructing the deceased after burial as an innovation due to the weakness of the hadith concerning it.

As for wiping the face with the hands after supplication (du‘a’), it has been established by a hadith that is hasan (good) with its corroborating evidence.

Regarding wiping the neck during ablution (wudu’), a narration has been reported concerning it, which Al-Albani described as fabricated (mawdu‘) and reprehensible (munkar).

As for the Tasbih Prayer, scholars have differed concerning its hadith, but the majority of verified scholars affirm its authenticity.