Why do Shi'a Muslims combine their prayers?

It is incumbent upon every Muslim to pray five times a day, at times prescribed by the Qur'an and the Sunna: from noon to sunset is the period for the zuhr and 'asr prayers; from sunset to the late night is the period for the maghrib and 'isha' prayers; and from first light to sunrise is the time for the fajr prayer.
The Shi'a believe that in the period between noon and sunset, both the ;zuhr and the 'asr prayers can be prayed together, the first four units of prayer pertaining to zuhr and the second set of four to 'asr. Therefore, one is allowed to pray these two sets of prayers any time within the prescribed period, without necessarily having to pray each separately, at the preferred time; however, it is better to separate the two and pray each at the preferred time, as we shall explain below. [1]

The Shi'a believe that in the period between noon and sunset, both the ;zuhr and the 'asr prayers can be prayed together, the first four units of prayer pertaining to zuhr and the second set of four to 'asr. Therefore, one is allowed to pray these two sets of prayers any time within the prescribed period, without necessarily having to pray each separately, at the preferred time; however, it is better to separate the two and pray each at the preferred time, as we shall explain below.

Imam Baqir said:

'When the sun begins to decline, the time for the zuhr and the 'osr begins; and when the sun sets, the time for the maghrib and the 'isha' begins. '[2]

Imam Sadiq said:

'When the sun reaches its height, the time for both the zuhr and the 'asr prayers begins, except that the zuhr prayer must be said before the 'asr. You are able to perform the prayers any time before the sun sets. '[3]

Imam Baqir relates that the Prophet used to pray the zuhr and the 'asr prayers together, without there being any reason or special circumstances for doing so.[4]
In principle, the permissibility of joining the two prayers together is agreed upon, in certain circumstances, by all schools of fiqh. On the days of Arafat and Muzdalifa [during the Hajj], all are agreed that the two prayers of zuhr and 'asr, as well as maghrib and 'isha', can be joined together; likewise, a majority of the Sunnis accept the joining of the prayers when travelling. What distinguishes the Shi'a from the other schools is that they go one step further. Based on the reasons given above and despite upholding the principle that it is preferable to pray the prayers separately and at their respective, specific times-they accept the permissibility of joining the prayers together in an unconditional manner. The wisdom of this position, as is evident in the hadiths brought forth in this regard, derives from the principle of making the religion of Islam easy to practice for the Muslims. For the Prophet himself, on numerous occasions, in the absence of any reason (such as travelling or sickness, and so on), prayed the two prayers together in order to make the burden of the religion light for his community, allowing him who so Wishes to pray the prayers together, and him who so wishes to pray them separately.

The wisdom of this position, as is evident in the hadiths brought forth in this regard, derives from the principle of making the religion of Islam easy to practice for the Muslims. For the Prophet himself, on numerous occasions, in the absence of any reason (such as travelling or sickness, and so on), prayed the two prayers together in order to make the burden of the religion light for his community, allowing him who so Wishes to pray the prayers together, and him who so wishes to pray them separately.

In his Sahih Muslim relates:

'The Messenger of God prayed the zuhr and the 'asr 'together, and the maghrib and the 'isha together, without his being a traveller or in fear [of being attacked by the enemy in war-time]. '[5]

The wisdom of this position is revealed in certain narrations; in one such we read:

'The Prophet joined together the zuhr and the 'asr, and the maghrib and the 'isha'. When asked about this, he said: I did 'this lest my community find hardship [in the performance of the obligatory duties of Islam]. '[6]

There are more than twenty-one narrations in the collections of sound hadiths that pertain to the Prophet's joining together of the two sets of prayers, some of them relate to times of travel, others to times of sickness, stormy weather and times when one is not travelling and has no problem. The wisdom behind this practice, as seen above derives from the principle of avoiding hardship and making the duties of religion easy to accomplish. It is on this principle that the Shi'i school have made it permissible to join the two sets of prayer together in an unconditional manner. The way the two prayers are joined is just the same as the way in which they are joined, for all Muslims, when travelling and at the occasions of Arafat and Muzdalifa [during the Hajj].

It is sometimes thought that the reason for joining the two prayers together is that the zuhr prayer be prayed at the last possible time (within the preferred period, that is, when the shadow of the sun-dial's pointer is the same length as itself), and that the 'asr then prayed at the very beginning of its preferred time. In such a way, the one praying will be able to pray each prayer within the preferred time, the one at the end of its period and the other at the beginning of its period. But such an idea contradicts the meaning of the narrations. For, as has been said, the way in which the prayers are to be joined is the way they are joined by all Muslims at Arafat and Muzdalifa. In other words, at Arafat, both the zuhr and the 'asr are prayed together at the time of zuhr, and at Muzdalifa, both the maghrib and the 'isha' are prayed together at the time of 'isha '.[7] Thus, for one who would join the two sets of prayers, it is this mode of joining the prayers performed by the Prophet that must be carried out; one cannot pray one prayer at the end of its preferred period and then the other at the beginning of its preferred period.

In some of the narrations, the wisdom of' joining the prayers is presented in terms of the ease and comfort of the community, in others in terms of relief of difficulty; the principal point is that the one who prays should be allowed to decide for himself whether to join the two sets of prayers together, for the sake of relieving him of any difficulty. 

In some of the narrations, the wisdom of' joining the prayers is presented in terms of the ease and comfort of the community, in others in terms of relief of difficulty; the principal point is that the one who prays should be allowed to decide for himself whether to join the two sets of prayers together, for the sake of relieving him of any difficulty. Also, one should note, on the basis of this explanation of the joining together of prayers, that the Prophet did not bring something new, insofar as a mode of joining the prayers was already permitted, even prior to his own action of joining the prayers: every Muslim could pray the zuhr at the end of its period and the 'asr at the beginning of its period.
The fuqaha' [jurists] of Shi'ism have written extensively on this matter, and those interested can consult their treatises of fiqh.

1. The preferred time of the zuhr prayer is from the moment the sun begins to decline to the time that the shadow of an indicator of a sun-dial is as long as the indicator itself; the preferred time of the 'asr prayer is until the shadow of the indicator is twice as long as the indicator.
2. al-'.Amili, Wasa'il al-Shi'a, vol. 3, ch. 4, narration no. 1.
3. Ibid., vol. 3, ch. 4, narration no. 4.
4. Ibid., vol. 3, ch. 4, narration no. 6.
5. Muslim, Sahih, vol. 2, p. 151, chapter, "On the joining together of the two prayers whilst at home".
6. See the commentary of Zarqani on the Muwatta'. of Imam Malik on the joining together of the two prayers whilst at home and journey¬ing, Muhammad b. 'Abd al-Baqi al-Zarqani, Sharh Zarqani (Cairo, n.d.), P· 294.
7. It is the principle of joining the two sets of prayers that is being stressed here; according to Shi'i fiqh, it is prefer¬able, if the two evening prayers are to be joined, that they be prayed at the time of maghrib, not 'isha', although it is permissible to join them at the time of 'isha' also.