The Categories of Al-Istihsaan:
The Istihsaan is divided in respect to the Daleel that is opposing to Al-Qiyaas into three categories:
1 - Istihsaan As-Sunnah:
That the Sunnah establishes that which obliges the rejection of Qiyaas in respect to a ruling upon a certain reality.
An example of this: The testimony (Ash-Shahaadah) of Al- Khuzaimah:
The Nabi (saw) specified Khuzaimah in respect to the acceptance of his testimony alone and making his testimony equal to that of two men. He (saw) said:
The one for whom Khuzaimah provides testimony then that is sufficient for him
(Abu Daawood, An-Nasaa’iy with the Lafzh (wording): ‘The Shahaadah of Khuzaimah is equal to the Shahaadah of two men’)
Consequnetly, the acceptance of the testimony of Khuzaimah reflects a departure from Qiyaas because Qiyaas does not accept the Shahaadah of a single man because the Nisaab (required quantity) for the testimony is two men or a man and two women. However, it is a departure from Qiyaas due to the mentioning of the text (i.e. the Sunnah).
2 - Istihsaan Al-Ijmaa’:
This is when the Qiyaas is abandoned in a Mas’alah (issue) due to the convening of an Ijmaa’ upon other than what the Qiyaas has led to.
An example of this:
The Messenger of Allah (saw) said:
Do not sell that which don’t have (Tirmidhi).
The Shaari’ (through the Sunnah) has forbidden the sale of that which does not exist (Ma’doom) and to make a contract upon that which does not exist (Ma’doom). However, the Ijmaa’ has convened upon the permissibility of al-Istisnaa’ (manufacturing) which represents a contract upon that which does not exist and is included within the forbiddance by Qiyaas.
3 – Istihsaan Ad-Daroorah and Al-Maslahah:
This is when the Hukm of Qiyaas is gone against due to a compelling Daroorah (necessity) or a Maslahah (interest) required to meet the need (Haajjah) or repel the Haraj (hard or difficult matter).
Example:
The Shar’a has explained that the hired person is not liable if he damages something that he has been given in his possession unintentionally and not due to a shortcoming. So if a person is hired to sew a garment for someone else for a period of a week then he is an Ajeer Khaass (private hired person). If he then damages the garment by his hand without it being deliberate he is not liable because his hand represents an Amaanah (trust) and the Messenger of Allah (saw) said:
There is no liability upon the thing that has been entrusted (Ad- Daaruqutniy).
And if another person was hired to sew a garment and he was somebody who would sew items of clothing for all of the people then he would be an Ajeer ‘Aamm (public hired person). Then if he was to damage an item of clothing that was in his hand then there would be know Damaan (liability) and that is because his hand is also a hand of Amaanah (i.e. that has been entrusted) and this is in analogy to the Ajeer Al-Khaass mentioned previously.
However, in accordance to Istihsaan (Istihsaan Al-Maslahah) the private hired person is not liable whilst the public hired person is liable and that is so that he does not accept or take on work that is beyond his capability or capacity.
The Istihsaan Al-Maslahah has gone against the established Hukm by Qiyaas due to regard being given to Daroorah and Maslahah. This is despite having been commanded to follow the Hukm Ash-Shar’iy irrespective of what the results may be.