“Nor does he speak from [his own] inclination. It is not but a revelation revealed.”[Quran 53:3-4]

Lexically, the word Sunnah has several, different yet close meanings. Sunnah may mean a way of life, or a path or behavior that is followed whether praiseworthy, or otherwise. Mostly, however, it refers to something good.
The Prophet sallallaahu `alayhi wa sallam (may Allah exalt his mention) said, "Whoever starts a good Sunnah he will get the reward for it and the reward of others who would do the same thing until the Day of Judgment. And whoever does a bad Sunnah he will have the punishment for doing it and the punishment of others who practice it." [Muslim]

Another Arabic root of the word Sunnah is bayaan, or making something clear through talking or acting. The most common meaning indicates that Sunnah is to initiate something or set an example to be followed. Hence, if a person started something that people then followed, he is considered to have established a Sunnah.
The Prophet sallallaahu `alayhi wa sallam ( may Allah exalt his mention ) said, "For any soul, unjustly killed, the first son of Aadam, Abel, will carry a burden of its shedding, for he was the first to begin the Sunnah (or crime) of murder." [At-Tirmithi]

As an Islamic term, scholars of the different disciplines of Sharee'ah (Islamic Law) have defined Sunnah in slightly different ways to suit their fields' perspectives. According to Legal theorists who typically regard the Sunnah as a source for the principles used in the derivation of rulings of various Islamic Jurisprudence matters, define it as "The statements, actions and approvals (or disapprovals) of Prophet Muhammad sallallaahu`alayhi wa sallam (may Allah exalt his mention)."

The jurists use the word Sunnah in two different ways. On one hand, like the Legal theorists, they define Sunnah as the statements, actions, and approvals of' the Prophet, sallallaahu `alayhi wa sallam (may Allah exalt his mention). On the other hand, and since the role of the jurists is to judge actions and indicate their rulings as obligatory, recommended, etc., they use the term Sunnah to indicate actions as being recommended or praise-worthy.

However, the definition of Sunnah, according to the scholars of Hadeeth, is more comprehensive for it is inclusive of everything related to the person and life of the Prophet sallallaahu`alayhi wa sallam (may Allah exalt his mention). They defined the Sunnah as "Anything narrated from or about the Prophet sallallaahu`alayhi wa sallam (may Allah exalt his mention) either before or after he became a prophet, of his statements, actions, confirmations, biography, and his physical character and attributes."

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VERY CLEAR!

Have already have the knowledge of what Sunnah is all about. Good job.

Jazakallahu khayran

Jazakallahu khayran

Good to have page like this. Jazakallah!