The root of their disagreement is this: Is one required to carry out only part of what the term applies to, or all of it? In the authentic ḥadīth of the Prophet—peace and blessings be upon him—related by Ibn ʿAbbās, he said, “I have been commanded to prostrate on seven limbs,” and among those he mentioned the face.
Hence, whoever held that the obligation is fulfilled by observing some of what the term “prostration” covers said: If he prostrates on either the forehead or the nose, that suffices. But whoever maintained that the very word “prostration” applies to the one who places his forehead on the ground but not to one who places only his nose, allowed prostration on the forehead without the nose. This in effect specifies which part whose performance discharges the duty among the things covered by the term, and it reflects the school of those jurists who differentiate between the parts of an act, judging that some parts fulfill the obligation while others do not. Reflect on this, for it is a foundational principle in this chapter. Otherwise, one might claim that if even a mustard seed’s weight of his nose touched the ground his prostration would be complete.
Those who believe the duty is to comply with everything denoted by the term insist that he must prostrate on both forehead and nose.
Al-Shāfiʿī remarks that any ambiguity arising from the wording is removed and clarified by the Prophet’s own practice, for he would prostrate on both nose and forehead. It is reported that he once finished one of his prayers with traces of mud and water upon his forehead and nose; therefore, his action serves to explain the concise ḥadīth.
Abū ʿUmar ibn ʿAbd al-Barr said: A number of ḥadīth specialists have cited the report of Ibn ʿAbbās and included in it both the nose and the forehead.
Qāḍī Abū al-Walīd added: Some narrators mention only the forehead, and both versions are found in Ṣaḥīḥ Muslim; this constitutes evidence for Mālik.
They likewise differed over whether it is a condition of prostration that the worshiper’s hands be uncovered and placed upon the surface on which the face rests. Mālik held: That is indeed a condition of prostration—I regard it as required for its completion. A number of scholars, however, considered that it is not a condition.
This same line of reasoning underlies their dispute about prostrating on the folds of one’s turban. On this matter people hold three views: one opinion forbids it; another permits it; and a third differentiates—either between prostrating on a few folds or on many, or between whether any part of the forehead actually touches the ground or not. This disagreement