ibn ʿUyaynah, from Jaʿfar ibn Muhammad, from his father, who said:

“ʿUthmān fell ill while he was at Minā. ʿAlī arrived and was asked, ‘Lead the people in prayer.’ He replied, ‘If you wish, I will lead you in the prayer of the Messenger of Allah—may Allah bless him and grant him peace—of two rakʿahs (units of prayer).’ They said, ‘No, only the prayer of the Commander of the Faithful’—meaning four rakʿahs. So he refused.” There is also a report from Ibn Masʿūd in the two Sahīh collections (1).

Scholars have differed over performing four rakʿahs while travelling, holding several views:

One view is that this is equivalent to performing the dawn prayer as four rakʿahs. This is the position of a group of earlier and later scholars, including Abū Hanīfah, Ibn Hazm, and other adherents of the Zāhirī school. According to Abū Hanīfah, if the worshipper sits for the time needed to recite the tashahhud (testimony of faith), his prayer is complete, and whatever he performs thereafter is treated as a separate voluntary prayer. If he does not sit for that length of time, his prayer is invalid. Ibn Hazm and others, however, hold that his prayer is invalid, just as they regard a dawn prayer performed as four rakʿahs as invalid.

Saʿīd narrated in his Sunan from al-Dahhāk ibn Muzāhim, who said:

“Ibn ʿAbbās said, ‘Whoever performs four rakʿahs while travelling is like someone who performs two rakʿahs when not travelling.’”

Ibn Hazm said:

“We have also transmitted a report from ʿUmar ibn ʿAbd al-ʿAzīz. When performing prayers in full while travelling, for whoever wished to do so, was mentioned to him, he said, ‘No. Prayer while travelling must be two rakʿahs; no other number is valid.’”