وَإِذَا ضَرَبْتُمْ فِى ٱلْأَرْضِ فَلَيْسَ عَلَيْكُمْ جُنَاحٌ أَن تَقْصُرُوا۟ مِنَ ٱلصَّلَوٰةِ إِنْ خِفْتُمْ أَن يَفْتِنَكُمُ ٱلَّذِينَ كَفَرُوٓا۟ ۚ إِنَّ ٱلْكَٰفِرِينَ كَانُوا۟ لَكُمْ عَدُوًّۭا مُّبِينًۭا
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.
And when you are going forth, travelling, in the land you would not be at fault if you shorten the prayer, by making it two [genuflexions] instead of four, if you fear that you may be afflicted by those who do not believe, that is, [if you fear] that you may be harmed [by them]: this [fear of affliction at the hands of the disbelievers] is [just intended as] an explication of the reality [of the situation] at that time and the point no longer applies. In the Sunna, it is pointed out that ‘travel’ (safar) means long-distance [travel], which is [approximately] 50 miles. God’s words ‘you would not be at fault’ should be understood as [denoting] a dispensation and not a requirement, and this is the opinion of al-Shāfi‘ī; the disbelievers are a manifest foe to you, their enmity being evident.