When the Messenger of Allah (ﷺ) intended to combine two prayers on a journey, he delayed the noon prayer till came the early time of the afternoon prayer, and then combined the two.
The Book of Prayer - Travellers
Sahih Muslim 704 b
Hadith Text
When the Messenger of Allah (ﷺ) intended to combine two prayers on a journey, he delayed the noon prayer till came the early time of the afternoon prayer, and then combined the two.
Scholarly Commentary
This noble hadith from Sahih Muslim establishes the permissibility of prayer combination (jam' al-salat) during travel, which is a concession (rukhsa) granted by the Shari'ah to alleviate hardship.
The Prophet (ﷺ) practiced what is known as "jam' al-ta'khir" (delayed combination), wherein he performed Dhuhr and 'Asr together during the time of 'Asr. This demonstrates that combination may be done by advancing or delaying, though this narration specifically illustrates the latter method.
Scholars differ regarding whether combination requires actual travel or mere intention to travel. The majority hold that one must have commenced the journey, while some require covering the specific distance that permits prayer shortening (approximately 48 miles).
The wisdom behind this concession reflects the mercy of Islamic law, recognizing the difficulties of travel and seeking to facilitate worship without undue burden upon the believer.
Legal Rulings
Combination is permissible for: travelers, those experiencing heavy rain or severe mud, and the sick who would face hardship in praying separately.
The prayers that may be combined are: Dhuhr with 'Asr, and Maghrib with 'Isha'. Fajr prayer is not combined with any other prayer.
When combining, one must maintain the sequence - performing Dhuhr before 'Asr and Maghrib before 'Isha' - and perform each prayer in its complete form unless one is also qualified to shorten them.