The Prayer of Fear

This ṣalāh is prescribed in the Qur'an; it is in verse 102 of Sūrat al-Nisāʾ. Allah (swt) says:

And when you — that is, the commander of an army — are among them and lead them in prayer, let a group of them stand in prayer with you and let them carry their arms, so they are standing in ṣalāh with their arms; and when they have prostrated, let them be in position behind you, and have the other group come forward which has not yet prayed, and let them pray with you, taking precaution and carrying their arms. Those who disbelieve wish that you would neglect your weapons and your baggage so they could come down upon you in one single attack. If you are troubled by rain or are ill, there is no blame for putting down your arms, but take precaution; indeed Allah has prepared for the disbelievers a humiliating punishment.

So the way this ṣalāh is performed, there are two opinions. One is that one part of the army prays behind the imām while the other part of the army is guarding. So this half that is praying with the imām would pray with the imām one rakʿah, and then the imām would stand up for the second rakʿah and would not move while they would finish their second rakʿah and give salām — which means that they prayed with the imām one rakʿah, and the imām is now waiting. The next group, the group that was guarding, would then step in and they would pray with the imām the second rakʿah, and then they would finish their second rakʿah alone. This is one opinion; it is the form that Ṣāliḥ ibn Khawwāt relates of the fear prayer at Dhāt al-Riqāʿ itself (Ṣaḥīḥ al-Bukhārī 4129). The other opinion is that the imām leads the first half in the two rakʿahs, and then they make salām, and then the next group comes in and prays another two rakʿahs with the imām. So the imām would end up praying four rakʿahs, while each half of the army would have prayed two rakʿahs; this is the form that Jābir ibn ʿAbdullāh relates of that same expedition (Ṣaḥīḥ Muslim 843). So these are the two opinions of how Ṣalāt al-Khawf is performed.

The lesson to mention here is the importance of ṣalāh: that even if you are afraid that the enemy might ambush you, you still have to pray. So if this is the case with the ones who are fighting in the path of Allah, who are afraid of death — they still have to pray the ṣalāh — what about somebody who has really nothing urgent, and nevertheless they neglect the ṣalāh? See, in Islam, every ʿibādah — every ʿibādah — has conditions where you do not have to do it, except ṣalāh. So, for example, the poor do not have to pay zakāh, the ill do not have to fast, the financially incapable does not have to make Ḥajj, and so on. This could go on with every ʿibādah except ṣalāh. You are not excused at all. No matter what, a Muslim has to pray. If you can't pray standing up, you pray sitting down. If you can't sit down, you lie down. Lying down, you move your head. If you can't move your head, you move your finger. If you can't move your finger, you blink with your eye. The point is, ṣalāh needs to be done. It must be done, and a Muslim is not excused from praying.