The Distinguished Jurists Primer by Ibn Rushd

It is unlikely for those who said that purification from filth is an emphatic sunna to say that it is an obligation for prayer, that is, a condition for it: validity, while those who maintained that it is an absolute obligation would sa; that it is an obligation for prayer^ but it is possible that they would not say this Two opinions of the school (Malik’s) are related from cAbd al-Wahhab. First that removal of uncleanliness is a condition for the validity of prayer, when ii possession of the means for doing so and in a state of remembering. Th' second opinion is that it is not a condition. The opinion that it is a conditioi does not conform with the better known opinion of the school that it is ai emphatic sunna. It conforms more with the opinion that it is an obligatioi when the capacity to remove (the uncleanliness is available) and when in a stat of remembrance. The issue had already preceded in the Book of Ritua Purification, and the reasons for disagreement were identified there.

The discussion relevant here is whether an absolute obligation that is relate* to prayer is necessarily an obligation of prayer also. The truth is that a thin; that is an absolute requirement does not necessarily become a condition for th validity of another required thing, [even if it occurs during it, except b; another command; similarly, an absolute command for a thing proscribe absolutely does not necessarily become a condition for the validity of another thing]?08 except by another command.