The Muslims are unanimously agreed that purification is obligatory for prayer.

What still needs clarification is what actually falls under the term “prayer.” Those who considered purification compulsory for a lone act of prostration differed among themselves:
• Some said that one must conclude it with the taslīm (closing salutation);
• others argued that he should pronounce two takbīrs (each time saying “Allāhu akbar”)—one to open the act and one for the prostration itself;
• still others maintained that he should recite the tashahhud (testification of faith) during it.

For none of these opinions is there any transmitted evidence whatsoever—neither from the Prophet, may Allah bless him and grant him peace, nor from any of the Companions. They are merely personal inferences, based on the assumption that the isolated prostration counts as prayer.

Some scholars went further and said, “Prayer cannot consist of less than two rak‘ahs (cycles of prayer); anything short of that is not prayer, except the single rak‘ah of Witr (the odd-numbered night prayer).” He supported his view with the report found in the Sunan collections, narrated by Ibn ʿUmar, that the Prophet said: “The prayers of the night and the day are offered two by two.” This was the position adopted by Ibn Ḥazm.