Bilangan Rak'at bagi Solat pada permulaan perintah solat

Pada mulanya selepas kejadian Isra' Mi'raj, bilangan rak'at untuk setiap waktu solat, iaitu  Fajr, Zuhr, Asr, Maghrib dan Isya' adalah 2.

Kemudian, apabila Rasul s.a.w. berhijrah, bilangan rak'at ditetapkan 4, tetapi bagi yang bermusafir, bilangan rak'at masih 2 ( bilangan yang asal ) ; 

HANYA untuk solat Mahrib (3)  oleh sebab ia adalah Solat Witr bagi siang hari dan untuk solat Fajr (2 rak'at - rak'atain) kerana bacaan (surah) nya adalah panjang. ( Bacaan surah Rasul s.a.w.yang terpendek untuk solat  Fajr adalah surah Al-Waqiah) .

Rujukan :

Narrated Aisha r.a. that the Salat (prayer) was prescribed as consisting of two Rak'at and was afterwards established as the prayer during travelling. And the prayer at the place of residence was completed [ Agreed Upon ]

In the version of Al-Bukhari : When (Allah's messenger s.a.w.) emigrated it was prescribed as four, but prayer while travelling was left according to the original prescription.

Ahmad added, 'Except the Maghrib (prayer) for it is the Witr (prayer) of the day; and it concerns Fajr (prayer), the recitation (of the Qur'an) is prolonged in it.

[ Bulugh-al-Maram : The Prayer of a Traveller and A Patient  no. 341 ]