A fourth opinion on the matter—and it is weak—holds that impurity is removed only during the prayer itself. Equally weak is the view of those who distinguish between acts of worship whose rationale is intelligible and those whose rationale is not, making the latter more emphatically obligatory. They differentiate between the command concerning purification from minor ritual impurity and the command concerning purification from physical filth, arguing that removal of filth is clearly intended for cleanliness, which belongs to noble character traits. By contrast, purification from minor ritual impurity has no apparent rationale, a point underscored by the fact that they would pray in their sandals—sandals that are almost inevitably soiled by impurities—and by their unanimous agreement that a small amount of certain impurities is excused.

Second Chapter: On Identifying the Categories of Impurity

With regard to the kinds of impurity, the scholars have unanimously agreed, concerning their very substances, upon four:

1. the carcass of a land animal that possesses flowing blood;
2. the flesh of the swine, regardless of how its life has ended;
3. the blood itself of a land animal possessing flowing blood when it separates—whether from a living or dead body—provided it is shed in quantity; and
4. human urine and excrement.

Most of them also deem wine impure, although some ḥadith scholars differ, and they disagreed about other matters as well. From this discussion arise seven principal issues.

Issue One

They disputed about the carcass of creatures that have no blood and about the carcass of sea creatures. One group held that the carcass of what has no blood is pure, and likewise the carcass of sea creatures; this is the position of Mālik and his companions. Another group judged the carcass of blood-bearing and bloodless creatures equally impure, excluding only the carcass of sea creatures; this is the view of al-Shāfiʿī, except for what is unanimously recognized as not being carrion at all, such as vinegar worms and other organisms that originate in foods. A third group placed land and sea carcasses on the same footing and excluded only the carcass of what has no blood; this is the doctrine of Abū Ḥanīfah.

The reason for their disagreement lies in how they understand the Almighty’s words, “Forbidden to you is carrion” (al-Māʾidah 5:3). They apparently agree that the verse employs a general wording while intending something specific, yet they differ over what that specific exception is. Some exclude both the carcass of sea creatures and that of bloodless creatures; some exclude only the carcass of sea creatures; and others exclude only the carcass of bloodless creatures. Their disagreement over these exceptions ultimately stems from their disagreement about the particular textual evidence.

Those who exempt what has no blood cite the implicit meaning of the authentic report from him—peace and blessings be upon him—regarding his instruction to immerse a fly if it falls into food. They say this indicates the purity of the fly, and the only reason for that is that it is bloodless.

As for al-Shāfiʿī, he holds that this ruling applies solely to the fly, on account of the Prophet’s—peace and blessings be upon him—words: “For indeed in…"