Muhammad Zafrulla Khan 
The Salat had been made obligatory while the Holy Prophet was still in Mecca, but except in the case of the Maghrib prayer service, which comprised three raka’as, the other services comprised only two raka’as. After the Migration to Medina the Holy Prophet, under divine direction, prescribed four raka’as for the three services other than Fajr and Maghrib, except that the old system continue in respect of services during a journey.
The Salat had been made obligatory while the Holy Prophet was still in Mecca, but except in the case of the Maghrib prayer service, which comprised three raka’as, the other services comprised only two raka’as. After the Migration to Medina the Holy Prophet, under divine direction, prescribed four raka’as for the three services other than Fajr and Maghrib, except that the old system continue in respect of services during a journey.
The Holy Prophet, peace be on him, laid the greatest stress, of
all forms of worship, on the Salat. He observed that during the Salat a
worshipper is in communion with his Maker. In his own case he was so fond of
Salat that in addition to the five prescribed services he stood in Prayer for a
long time in Tahajjud, after midnight, so that sometimes his feet would become
swollen. He often observed that the Salat was the greatest comfort of his soul.