The term Sunnah comes from the root word sanna, which means to pave
the way or make a path easily passable, such that it becomes a commonly
followed way by everyone afterwards. Thus sunnah can be used to describe
a street or road or path on which people, animals, and cars travel.

Additionally, it can apply to a prophetic way, i.e. the law that they brought
and taught as an explanation or further clarification of a divinely revealed
book. Normally, the prophetic way includes references to his sayings,
actions, physical features and character traits.
From the Islamic standpoint, Sunnah refers to anything narrated or related
about the Prophet Muhammad (pbuh), authentically traced to him
regarding his speech, actions, traits, and silent approvals, before and after
the revelation.

Each narration is composed of two parts: the isnad and the matn. The isnad
refers to a chain of people who narrated a particular narration. The matn is
the actual text of the narration. The isnad must comprise upright and
sincere individuals whose integrity is unquestionable.

The Speech of Prophet Muhammad (pbuh)
The speech of Prophet Muhammad (pbuh) refers to his sayings. For
example, he said:

“Actions are judged by their intentions; everyone will be rewarded
according to his/her intention. So whoever migrates for the sake
of Allah and His Prophet then his migration will be noted as a
migration for the sake of Allah and His Prophet. Conversely, one
who migrates only to obtain something worldly or to marry a
woman, then his migration will be worth what he had intended.”
[Bukhari].

The Prophet (pbuh) also said: “Whoever believes in Allah and the
Last Day, should say something good or keep quiet.
The above two accounts clearly show that the Prophet (pbuh) spoke these
words. Consequently, these are known as his speech.

The Actions of Prophet Muhammad (pbuh)
His actions pertain to anything he did, as authentically reported by the
Sahabah (Companions). For instance, Hudhayfah reported that whenever
the Prophet (pbuh) got up at night, he would clean his teeth with a toothstick.
Also A’ishah reported that the Prophet (pbuh) loved to do
everything starting with the right side - putting on shoes, walking, cleaning
himself, and in all his affairs generally.

The Silent Approvals of Prophet Muhammad (pbuh)
His silent approvals on different issues meant his not opposing or minding
what he saw, heard or knew of the actions or sayings of his Companions.
On one occasion, for example, the Prophet (pbuh) learned of actions of
some of his Companions from other Companions. Soon after the battle of
Khandaq, Prophet Muhammad (pbuh) gave the order to the Companions to
move quickly to surround the tribe of Banu Quraydah, encouraging them
to hurry so that perhaps they would pray ‘Asr (the late afternoon prayer)
there.

Some of the Companions of the Prophet (pbuh) responded
immediately and left without praying ‘Asr. They arrived after sunset,
pitched camp and prayed ‘Asr- after sunset. At the same time another
group of Companions formulated their judgment differently. They thought
that the Prophet (pbuh) was merely encouraging them to hasten to their
destination, rather than to delay ‘Asr until after sunset. Consequently, they
decided to stay in Madinah until they had prayed ‘Asr. Immediately
thereafter, they hastened towards the tribe of Banu Quraydhah.

When the Prophet (pbuh) was told of how each group responded differently to his
announcement, he (pbuh) affirmed both judgments.

Physical and Moral Traits of Prophet Muhammad (pbuh)
Everything authentically narrated concerning the Prophet’s complexion and
the rest of his physical features is also included in the definition of sunnah.
Umm Ma’bad described what she saw of the great Prophet (pbuh). She
said:

“I saw a man, his face radiant with a bright glow, not too thin or
too fat, elegant and handsome. His eyes had a deep black hue with
long eyelashes. His voice was pleasant and his neck long. He had a
thick beard. His long black eyebrows were beautifully arched and
connected to each other. In silence, he remained dignified,
commanding utmost awe and respect. When he spoke, his speech was
brilliant. Of all people he was the most handsome and the most
pleasant, even when approaching from a distance. In person, he was
unique and most admirable. Graced with eloquent logic, his speech
was moderate. His logical arguments were well organized as though
they were a string of gems. He was not too tall or too short, but
exactly in between. Among three, he appeared the most radiant and
most vibrant. He had companions who affectionately honored him.
When he spoke, they listened to him attentively. When he gave
orders, they were quick to execute them. They rallied around him
guarding him. He never frowned or spoke frivolously.” [Hakim]

Along with his physical features, his Companions also described his habits
and behavior with people. Once Anas reported:

“I served the Prophet of Allah (pbuh) for ten years. Never once
did he so much as express any bit of displeasure nor did he ever
ask ‘Why did you do it?’ for something I did or ‘Why didn’t you do
it?’ for something I didn’t do.”

From the above we can clearly see that when the term sunnah appears in a
general context referring to Prophet Muhammad (pbuh) it comprises
anything narrated about the Prophet (pbuh) and authentically traced to him.
Once a Muslim learns of the authenticity of any narration, he/she is obliged
to follow and obey it accordingly. Such obedience is mandated by Allah as

He declares
“…and obey Allah and His Prophet and do not turn away when you
hear (him speak).” [8:20]

At times, some Muslims are perplexed when people say that sunnah is
something only recommended and is not mandatory. Thus they conclude
that we are only required to follow the Qur’an and not the Sunnah. Such an
argument results from a gross misunderstanding. Scholars of Islamic
jurisprudence use the term sunnah to denote what is authentically
established of Prophet Muhammad (pbuh) in deeds which were not
subsequently made mandatory by Allah.

They further hold that this includes any saying of Prophet Muhammad
(pbuh) where he encourages Muslims to do a particular task and
compliments those who imbibe such attributes. Thus to them, the term
sunnah denotes what is authentically established of Prophet Muhammad
(pbuh) in deeds which he did voluntarily and which were not subsequently
made mandatory by Allah. They further hold that this includes any saying
of Prophet Muhammad (pbuh) where he encourages Muslims to do a
particular task and compliments those who imbibe such attributes. Thus to
them, the term sunnah refers to what is “recommended” and is not
mandatory (fard or wajib).

From the above, we can clearly see that the term sunnah takes on different
meanings when used by different Islamic disciplines.