a shortened midday prayer, so the sunnah prayer associated with the midday prayer also applies to it. This is mistaken for two reasons.
First, by the agreement of the Muslims, Friday prayer has distinctive rulings that set it apart from the daily midday prayer, even if it is called a shortened midday prayer. Friday prayer must be performed within its prescribed time and cannot be made up afterward, whereas the midday prayer can be made up. Friday prayer also requires a certain number of worshippers, permanent residence, the imam’s permission, and other conditions, none of which is required for the midday prayer. The rulings of Friday prayer therefore cannot be derived from those of the midday prayer when Friday prayer has distinctive rulings that set it apart. Since Friday prayer shares some rulings with the midday prayer but differs from it in others, the disputed issue cannot be assigned to either category without evidence. There is no stronger basis for treating the sunnah prayer as a point of similarity than as a point of difference.
The second reason is this:
Even supposing that it is a shortened midday prayer, the Prophet (may Allah bless him and grant him peace) did not offer the sunnah prayer associated with the shortened midday prayer while travelling, either before or after it. He offered it only when he performed the midday prayer in full, as four rakʿahs. Since his practice regarding the shortened midday prayer differed from his practice regarding the full prayer, what they have cited is evidence against them, not in their favour. Moreover, the reason warranting the omission of part of the obligatory prayer warrants, all the more, the omission of its regular sunnah prayer. As one of the Companions said:
“If I were going to offer voluntary prayers, I would have performed the obligatory prayer in full.”
For if it were recommended for a traveller to pray four rakʿahs, it would be more appropriate for him to offer the midday prayer as four rakʿahs than to offer two obligatory rakʿahs and two sunnah rakʿahs.