As-sabab (the Cause)
Its definition:
As-Sabab linguistically means: That which arrives by it to a certain intended matter and for that reason the rope and the road are called a Sabab because each of them arrive to an intended matter.
As for the Sabab as a type from among the types of Hukm Ash-Shar’iy Al-Wad’iy then the Usooliyeen define it as:
The Sabab is a Wasf (description) Zhaahir Mundabit that the Shar’iy Daleel guides to as being an indicator for the presence of the Hukm.
The meaning of Zhaahir: That it is Mahsoos (sensed) and not Khafiy (hidden/concealed), that the human senses it with his senses and his Aql (mind).
The meaning of Mundabit: It means that when this description (Wasf) is found then the Hukm is also found as the Sabab and the Musabbab (the cause and caused matter) are connected or tied together in presence and non-presence.
An example of that is the Qawl of Allah Ta’Aalaa:
Establish prayer at the decline of the sun [from its meridian] (Al-Israa’ 78)
Or the statement of the Messenger (saw):
The time of the Zhohr prayer is when the sun declines (i.e. from the meridian)
So the Aayah and the Hadeeth both explain that the decline or passing of the sun (Zawaal) from the meridian is the Sabab (cause) for the identification of the existence of the Salaah. The meaning of that is that if this time comes into being then the Salaah of Zhohr comes into being and then it is allowed to perform it when the conditions (Shuroot) are met.
Consequently, the Sabab is an ‘Amaarah’ (sign or indicator) for the presence or non-presence of the Salaah. As for the obligation of the Salaah, then this is from the Ahkaam At-Takleefiy and its Daleel is the Qawl of Allah Ta’Aalaa:
And establish the Salaah (An-Nur 56).
And:
Verily, prayer has been decreed upon the believers a decree of specified times (An-Nisaa’ 103).
The same applies to the Sabab of the Sawm (fasting). Allah (swt) said:
So whoever sights [the new moon of] the month, then he should him fast it (Al-Baqarah 185).
And the Messenger of Allah (saw) said:
Fast when you see it
(Ahmad and verified as Saheeh by At-Tirmidhi)
These two texts explain that the sighting of the Hilaal (new moon) of Ramadhaan is the Sabab for the presence of the fasting of Ramadhaan.
Similarly, the attainment or reaching of the Nisaab is the Sabab for the presence of the Zakaah, the Idtiraar (necessity) is the Sabab for the permissibility of eating the Maitah (carrion meat) and the Shar’iyah ‘Uqood (contracts) are the Sabab for the permissibility to benefit from or transfer property (i.e. to take ownership and dispose of it).
The Sabab is therefore the indicator for the presence or non-presence of the Hukm and there must be a Daleel Shar’iy that indicates this Sabab. That is because the Shar’iy Sabab must have a Daleel Shar’iy that guides to it for it to be taken otherwise it would not be considered to be a Shar’iy Sabab for the presence of the Hukm Ash-Shar’iy.
In addition, the presence of the Hukm Ash-Shar’iy rests upon the presence of the Shar’iy Sabab so that in its absence the Hukm is also absent. Some have defined the Sabab based upon this angle and so they stated: ‘The Sabab is what necessitates by its presence the presence (of the Hukm) and necessitates by its absence the absence (i.e. of the Hukm)’.
As such, the Shaari’ (Legislator) addressed the Mukallaf with the Hukm Ash-Shar’iy At-Takleefiy and put down a sign or indicator that guides to the presence of the Hukm and this sign or indicator is the Sabab Ash-Shar’iy.