The valid „Illah is the Shar‟ai „Illah that is mentioned in the text from Qur'an and Sunnah, for only these two are the Shar‟ai texts. Therefore, the „Illah upon which the reasoned Hukm Shar‟ai is built is a Shar‟ai „Illah and not a rational „Illah. In other words, „Illah must be mentioned in the text either explicitly or implicitly or by deduction or through Qiyas. This „Illah is connected with the reasoned Hukm in presence and absence. Thus the rules revolve with their „Illal. So we find a thing is prohibited in a situation due to the existence of a Shar‟ai „Illah, and if this „Illah disappears that very thing becomes permissible. So the Hukm Shar‟ai revolves with the „Illah in existence and in absence, thus when it exists the Hukm exists, and if the „Illah does not exist the rule doesn't exist either.

However, the absence of the rule due to the absence of the „Illah does not at all mean that the Hukm Shar'ia has changed, rather the Hukm Shar‟ai of the question remains as it is, without change. It is only the rule no longer applied due to the absence of the „Illah, and will be applied once the „Illah returned.

The relationship of the rule with the „Illah in existence and in absence does not mean that the rules change due to the change of the time and place. Thus claiming that bringing about the benefit and preventing corruption is the „Illah of the Hukm Shar‟ai, which changes as the time and place change, so the Hukm Shar‟ai changes accordingly is false. This is because bringing about benefit and preventing harm are not at all the „Illah of the Akham, since no text came to denote that bringing about benefit and preventing corruption are „Illah for all the Akham, nor to denote that they are a „Illah for a specific rule. Thus, it cannot be taken as a Shar‟ai „Illah.

Moreover, the Shar‟ai „Illah is that which is taken from a Shar‟ai text and therefore should be restricted to it and its meaning. The Shar‟ai text has neither indicated that bringing about a benefit nor warding off corruption as being the „Illah. That which is brought in the text is not indicated by the time or the place nor indicated by the action itself. It is rather indicated by the text in manifesting the „Illah of the rule. This text never changes, so no consideration is given to the time and place in this context, nor is there a value to bringing about benefit and preventing corruption. Accordingly, Ahkam Shara'iah do not change with the change of time and place, they remain as such regardless of the change of times and places.

As for the change of traditions and customs of people, this does not have an effect in changing the rule, for the tradition is not an „Illah of the Hukm Shar‟ai nor a source for it. The traditions may agree or disagree with the Shar‟a; If they disagree with the Shar‟a then the Shar‟a has come to abrogate and change them, since the function of the Shar‟a is to change the corrupted traditions and customs, because they are the factors that cause corruption of the society. Therefore, they are not taken as a source for the Hukm Shar‟ai nor an „Illah for it. However, if the traditions were in agreement with Shar‟a, then the rule is proved by its Shar‟ai evidence and by its Shar‟ai „Illah and not by these traditions, even if these traditions do not contradict the Shar‟a. Therefore, the customs cannot rule over the Shar‟a, rather the Shar‟a rules over the traditions and customs. Accordingly, the Ahkam Shar'iah have their own evidence which is the text and they have Shar‟ai „Illah and the traditions and customs are not a part of that at all.