The shortening of prayers during travel (ṣalāt at-taqseer -صلاة التقصير) represents a regulatory provision that highlights the flexibility and essence of Islam in worship matters. It is a confirmed Sunnah that, following the unanimous opinion of the scholars, should be preserved and not neglected.
Allāh ﷻ says in the holy Qurʾān:
وإذا ضربتم في الأرض فليس عليكم جناح أن تقصروا من الصلاة إن خفتم أن يفتنكم الذين كفروا
And when you go forth on earth [on Ṣafar], you will incur no sin by shortening your prayers.
Ṣafar, [travel] as deducted from the Qurʾānic verse, and the various derivations from Sunnah, is not a matter of distance taken, but a state of mind. Any traveling that is permitted [not one taken in order to commit sins or disobedience], which falls within the linguistic definition of the word Ṣafar would suffice to shorten one’s Ṣalāh.
You are a musāfir when you travel outside of your city to a distance that you as a reasonable person will say that this is a travel, be it short or long. It is up to your mindset, your culture, your land’s customary practice [عُرْفُ -urf], or your movement habits that you know when you are musāfir and when you are not. There is nothing in the sunnah which confines this general term [Ṣafar] to any particular meaning.
The Prophet ﷺ used to shorten his prayers [Qasr] whenever he was on a journey [Ṣafar]. The prophet ﷺ is reported to have said: “Allāh likes His servants to undertake the legal concessions given to them in the same way as He likes them to observe their obligations."
In general, the majority of scholars believe that shortening the prayer [although not Wājib - not obligatory], is considered Mustahabb, that is, recommended. It is reported in a ḥadīth narrated by ʿĀʾisha bint Abī Bakr (may Allah be pleased with her) that when prayers were initially prescribed, they consisted of two rakaʿāt each. Later, the prayer during travel remained the same while that for non-travelers was completed.
The view that shortening the prayers is preferable [mustahabb], is as well supported by the fact that the Prophet ﷺ shortened the prayers in all of his journeys, and there is no authentic report to indicate that he ever offered the prayer in full when he was travelling. When you are in a state of Ṣafar, you are rewarded by Allāh extra for the shortening, by praying the four rakaʿāt as two, not for praying by completing the four rakaʿāt.
ʿAbd Allāh ibn ʿUmar, a companion of the Prophet صلى الله عليه وسلم, reported in a ḥadīth: "I traveled with the Prophet ﷺ, with Abū Bakr, and with my father ʿUmar, and in every journey, we always prayed Qasri."
Nevertheless, if a person performs for whatever reason a full prayer [four rakaʿāt] when they are travelling, the prayer is valid. They are not sinful, their prayer is permissible, but they have gone against Sunnah.
The situation where a traveler is instead required to pray the full ṣalāt [four rakaʿāt] without shortening, is if he prays behind a resident in a congregation [jamā’ah]. Then he has to fulfil with the imām, based on the following recommendation by the prophet ﷺ: “The Imām was appointed to be followed, so do not differ over him” [جعل الإمام ليؤتم به فلا تختلفوا عليه]
Schools agree that the shortening of prayers during the journey (Qasr) is limited to the four obligatory prayers, ṣalāt al-ẓuhr, ṣalāt al-ʿaṣr, and ṣalāt al-ʿishā, which will be performed in two rakaʿāt. The other two obligatory prayers, ṣalāt al-Fajr and ṣalāt al-maġrib, remain unchanged.
There are a number of opinions as to when Qasr begins. However, the overwhelming majority of the ṣaḥābah [companions] and tābiʿūn [followers] had one opinion. This vast majority’s opinion is that Ṣafar begins when you travel outside the walls of the city, the final habitations of the city of residence.
And this is proven in the ḥadīth narrated by Anas ibn Mālik when he said: “we prayed Dhuhri four rakaʿāt when in al-Madīna, then when we got to Dhul-Ḥulayfah we prayed two rakaʿāt”. Dhul-Ḥulayfah is literally a ten-minute drive from al-Madīna, it is outside the city [of al-Madīna], and safar had begun.
As to how long you can do Qasr for, there is no question about the timeframe of the Ṣafar itself. The prophet ﷺ did not explicitly state that you may continue doing qasr for some specific days and then you must swap over. In the famous books of ḥadīth there is nothing like this explicit however. What we have, are derivations. All the opinions derived are extracted from the life of the prophet. It is authentically reported that Ibn ʿUmar and others did qasr for more than six months. And he [Ibn ʿUmar] was saying: If I were determined to reside, I would have performed the prayers in full” The above scenario can serve as an evidence that, after arriving on the temporary destination, if you genuinely do not know when you will return, when every single day presents the potential of you returning, every day is a state of uncertainty, then in this case your ruling is the ruling of al-müsâfir, and therefore you can go ahead performing Qasr.
But when you have a good idea that you are staying at your destination for a specific period and you are not determined to reside, then you bring the niyyat of al-müsâfir for that explicit period and do Qasr throughout that specific time of stay.
Abbas Kiwuwa