a traveller intended to pray four rak‘ahs, doing so would be disliked for him, and the Sunnah would be to pray two. Imām Ahmad’s explicit statements support precisely this view.
The scholars have differed over offering four rak‘ahs while travelling: is it forbidden, disliked, merely a departure from what is preferable, or preferable? There are four views:
The first is the view of Abū Hanīfah and one view reported from Mālik.
The second is another view reported from Mālik, and also from Ahmad.
The third is a view reported from Ahmad and the sounder of al-Shāfi‘ī’s two views.
The fourth is another view held by al-Shāfi‘ī. This fourth view is unquestionably mistaken, and the third is weak. The tenable position is that offering four rak‘ahs is either forbidden or disliked. Some of the Companions used to offer four, and the others would disapprove, but not as they would disapprove of someone committing a forbidden act; rather, their disapproval was that shown towards someone doing something disliked.
As for the words of Allah Most High:
“When you travel throughout the land, there is no blame upon you for shortening the prayer if you fear that those who disbelieve may harm you.”
Here He made shortening conditional upon two causes: travelling through the land and fearing harm from those who disbelieve. This is because shortening, in its unrestricted sense, encompasses both reducing the number of rak‘ahs and abridging the prayer’s actions and essential elements, such as gesturing for bowing and prostration. This form of shortening is prescribed only when both causes are present.