سُورَةُ النِّسَاءِ
Surah An-Nisaa·4:101
وَإِذَا ضَرَبْتُمْ فِي الْأَرْضِ فَلَيْسَ عَلَيْكُمْ جُنَاحٌ أَنْ تَقْصُرُوا مِنَ الصَّلَاةِ إِنْ خِفْتُمْ أَنْ يَفْتِنَكُمُ الَّذِينَ كَفَرُوا ۚ إِنَّ الْكَافِرِينَ كَانُوا لَكُمْ عَدُوًّا مُبِينًا١٠١
AND WHEN you go forth [to war] on earth, you will incur no sin by shortening your prayers if you have reason to fear that those who are bent on denying the truth might suddenly fall upon you: for, verily, those who deny the truth are your open foes.