And do not weaken in pursuit of the enemy. If you should be suffering - so are they suffering as you are suffering, but you expect from Allāh that which they expect not. And Allāh is ever Knowing and Wise.
The Order for Ample Remembrance After the Fear Prayer
Allah commands Dhikr after finishing the Fear prayer, in particular, even though such Dhikr is encouraged after finishing other types of prayer in general. In the case of Fear prayer, Dhikr is encouraged even more because the pillars of the prayer are diminished since they move about while performing it, etc., unlike other prayers. Allah said about the Sacred Months,
فَلاَ تَظْلِمُواْ فِيهِنَّ أَنفُسَكُمْ
(so wrong not yourselves therein), even though injustice is prohibited all year long. However, injustice is particularly outlawed during the Sacred Months due to their sanctity and honor. So Allah's statement,
(In Islamic legal terminology, Safar means journey or travel; Qasr refers to the making of one's Salah short while in that status. Thus, four obligatory Raka’ at of Zuhr, 'Asr and 'Isha are reduced in number and confined to two Raka'at only.)
Rulings:
1. Full Sarah is made in a journey which is less than 48 miles.
2. If, after reaching the destination at the end of the journey, one intends to stay there for less than fifteen days, rules relating to 'journey' will continue to apply to him, that is, the obligatory four Raka'at of Salah will be reduced to half. This is Qasr. Now, if one intends to stay at one place for fifteen days, or more, it will become his place or country of residence. Here too, Qasr will not be observed as it was not observed in his original home country, that is, full Sarah will be performed.
Though Muslims rely entirely on God, they have been instructed to be ready with the necessary means of defence against their enemies. This is so because help from God reaches the recipient through tangible means. If the Muslims did not prepare for their defence, it would be like not taking hold of the receptacle through which God’s help could reach them. The difficulties faced by the Muslims in this world are a part of God’s scheme to create such conditions of trial as will enable Him to judge who remains steadfast and who is a reckless victimiser of his fellow men. During the struggle between truth and untruth, sometimes the believers are defeated and harmed. This causes pessimism among some of them. But in such adversities, God’s providence lies hidden; they occur so that man’s repentance will be the greater and, in turning to God, he will make himself more deserving of His benevolence.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.