النساۤء — An-Nisa' Ayat 101
وَاِذَا ضَرَبْتُمْ فِى الْاَرْضِ فَلَيْسَ عَلَيْكُمْ جُنَاحٌ اَنْ تَقْصُرُوْا مِنَ الصَّلٰوةِ ۖ اِنْ خِفْتُمْ اَنْ يَّفْتِنَكُمُ الَّذِيْنَ كَفَرُوْاۗ اِنَّ الْكٰفِرِيْنَ كَانُوْا لَكُمْ عَدُوًّا مُّبِيْنًا
Wa iżā ḍarabtum fil-arḍi fa laisa ‘alaikum junāḥun an taqṣurū minaṣ-ṣalāh(ti), in khiftum ay yaftinakumul-lażīna kafarū, innal-kāfirīna kānū lakum ‘aduwwam mubīnā(n).
"And when you travel throughout the land, there is no blame upon you for shortening the prayer, [especially] if you fear that those who disbelieve may disrupt [or attack] you. Indeed, the disbelievers are ever to you a clear enemy."