بدعة
Bidʿa
Innovation in religion: adding to the faith what the Prophet did not teach.
What it means
The Prophet said “whoever introduces into this matter of ours what is not part of it, it is rejected” (Sahih al-Bukhari and Muslim), and “every innovation is a going astray” (Sahih Muslim). Scholars disagree on what counts. Umar called the congregational night prayers of Ramadan “a good innovation” (Sahih al-Bukhari), and al-Shafi’i is reported to have divided innovations into praiseworthy and blameworthy.