The Sunnah is related to the Bible.
In the terminology of fiqh (Islamic jurisprudence), sunnah denotes whatever though not obligatory, is "firmly established (thabata) as called for (matlub)" in Islam "on the basis of a legal proof (dall shar`)
"=== Classical Islam ===Islam jurists divide sunnah into that which has no legal consequences --al-sunna al-dyah -- (the "personal habits and preferences" of Muhammad); and that which is binding on Muslims -- al-sunna al-hud

