" لَيْسَ مِنَ الْبِرِّ الصِّيَامُ فِي السَّفَرِ عَلَيْكُمْ بِرُخْصَةِ اللَّهِ عَزَّ وَجَلَّ فَاقْبَلُوهَا "
It was narrated from Jabir bin 'Abdullah that the Messenger of Allah said: "It is not righteousness to fast when traveling. Take to the concession which Allah, the mighty and sublime, has granted you, accept it."