The authority and excellence of the Sunnah, the normative mode of conduct of the Prophet (pbh), is mandated in the Qur'an itself, even though the term itself does not occur there with the same meaning. Certain aspects of the Sunnah are obligatory for the Muslim to follow; these include those several instances where the Sunnah clarifies the mode of implementation of a Qur'anic injunction, as is the case with prayer. A number of jurists hold, in fact, the Sunnah is a source of legal authority independent of the Qur'an. Other dimensions of the Sunnah are non-obligatory; to observe them is meritorious, but to omit them is not sinful. These include certain acts of devotion in which the Prophet (pbh) would engage. Finally, there are those matters in which the Prophet (pbh) was exercising his personal taste or judgment in matters not intrinsic to his prophetic mission; these must be regarded as incidental to the Sunnah.