Tafsir of An-Nisa' 4:103

(Then when you have completed the prayer), meaning: when you have performed the prayer of fear in the manner already described and finished it, (then remember Allah while standing, sitting, and [lying] on your sides); meaning: continue to remember Him, the Glorified, in all states, even during racing, engaging in combat, and archery. It is narrated from Ibn Abbas—may Allah be pleased with them both—that he said following his exegesis of this: "Allah, the Exalted, has not excused anyone for abandoning His remembrance except the one whose intellect is overwhelmed."

It has been said: The meaning is, "And when you intend to perform the prayer and the fear intensifies or the battle becomes fierce, then pray however you are able." This aligns with the Shafi'i school regarding the obligation of prayer during combat and the impermissibility of delaying it beyond its time. In such a case, the worshiper is excused from facing the Qibla due to the necessity of combat, not, for instance, the veering of a mount, provided the separation is not prolonged. Similarly, [the performer is excused for] excessive movements necessitated by need, according to the more correct opinion; [this does not include] shouting or speech without necessity, even if the need calls for it, such as alerting someone who is feared to be in mortal danger, urging on horses, or declaring that one is a certain person famous for bravery, due to the rarity of the need. There is no making up [of the prayer] (Qada) once security is achieved. Yes, if they prayed in that manner due to a group they perceived—even through the report of a just witness—to be an enemy, and it then becomes clear there was no enemy, or that there was something preventing them from reaching them, such as a trench, or that there was a fortress nearby where they could have taken refuge but were besieged within it, then they must perform Qada, according to the most apparent opinion. It is not hidden that carrying the verse to mean this is extremely far-fetched.

(Then when you are secure), meaning: when you have settled, as Qatadah and Mujahid have said. This refers back to the words of the Almighty: "...and when you travel throughout the land." Since "traveling" (Darb) implies movement and agitation, and was used as a metonym for journeying, it is fitting that "security" (Itmi'nan) should be used as a metonym for settling. Its origin is stillness and stability. [Meaning:] When you have settled from your journeying and travel in your cities, (then establish prayer), meaning: perform the prayer whose time has entered, complete it, balance its pillars, observe its conditions, and safeguard its limits.

It has been said: The meaning is, "So when you are settled, then complete the prayer," meaning: the genus of prayer, with balanced pillars, and do not pray it while walking, riding, or sitting. This is what is narrated from Ibn Zayd. It has also been said: The meaning is, "So when you are secure in general, then perform Qada of what you prayed in those states of anxiety and agitation." This has been attributed to al-Shafi'i—may Allah be pleased with him—but it is not correct, given what you know of his school, for none can inform you like one who is expert.

(Indeed, prayer has been upon the believers a decree), meaning: written and obligatory, (timed), restricted to specific times. It is not permissible to move it out of its times under any circumstances. Therefore, it must be established during travel as well. It has been said: The meaning is that it was, upon them, an obligatory command, measured in residency as four rak'ahs and in travel as two rak'ahs; thus, it must be performed at every time according to what has been measured for it. This verse has been used as evidence by those who interpreted the "remembrance" mentioned previously as meaning "prayer," and they made it obligatory during the state of combat, contrary to the school of Imam Abu Hanifah—may Allah be pleased with him.