according to many scholars, on account of travel, illness, or similar valid excuses. As for delaying a daytime prayer until night, or a nighttime prayer until day, the scholars agree that this is not permissible because of illness, travel, any other occupation, or work at a trade. Indeed, Umar ibn al-Khattāb, may Allah be pleased with him, said: “Combining two prayers without a valid excuse is a major sin.” However, a traveller prays two units; he is not obliged to pray four. The scholars agree that two units suffice for a traveller on a journey that qualifies for shortening the prayer.

Anyone who says that every traveller must pray four units is like someone who says that a traveller must fast the month of Ramadan. Both views are misguidance contrary to the consensus of the Muslims. Anyone who holds either view must be called upon to repent; if he does not repent, he is put to death.

The Muslims agree that a traveller has discharged his obligations if he performs four-unit prayers as two units, the dawn prayer as two units, and the sunset prayer as three units, and does not fast during Ramadan but makes up the missed fasts later. As for someone who fasts the month of Ramadan while travelling or prays four units, there is a well-known disagreement among the scholars: some hold that this does not discharge his obligation.

Thus, the Muslims agree that a sick person may postpone fasting, but they also agree that he may not postpone prayer. Likewise, the Muslims agree that a traveller may postpone fasting, but they also agree that he may not postpone prayer.