4:101

وَإِذَا ضَرَبْتُمْ فِي الْأَرْضِ فَلَيْسَ عَلَيْكُمْ جُنَاحٌ أَن تَقْصُرُوا مِنَ الصَّلَاةِ إِنْ خِفْتُمْ أَن يَفْتِنَكُمُ الَّذِينَ كَفَرُوا إِنَّ الْكَافِرِينَ كَانُوا لَكُمْ عَدُوًّا مُّبِينًا

Transliteration:

Wa-itha darabtum fee al-ardi falaysa AAalaykum junahun an taqsuroo mina alssalati in khiftum an yaftinakumu allatheena kafaroo inna alkafireena kanoo lakum AAaduwwan mubeenan

Word by Word:

And when you travel in the earth then not upon you (is) any blame that you shorten [of] the prayer if you fear that (may) harm you those who disbelieved. Indeed, the disbelievers are for you an enemy open.

Translations:

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.

When ye travel through the earth, there is no blame on you if ye shorten your prayers, for fear the Unbelievers May attack you: For the Unbelievers are unto you open enemies.

And when ye go forth in the land, it is no sin for you to curtail (your) worship if ye fear that those who disbelieve may attack you. In truth the disbelievers are an open enemy to you.

And when you journey in the earth, there is no blame on you if you shorten the prayer, if you fear that those who disbelieve will give you trouble. Surely the disbelievers are an open enemy to you.

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.