"O Messenger of Allah, I feel able to fast while traveling." He said: "If you wish then fast and if you wish then do not fast." (Using translation from Nasāʾī 2298)
يَا رَسُولَ اللهِ إِنِّي أَسْرُدُ الصَّوْمَ فَلَا أُفْطِرُ أَفَأَصُومُ فِي السَّفَرِ؟ قَالَ «إِنْ شِئْتَ فَصُمْ وَإِنْ شِئْتَ فَأَفْطِرْ»