وَعَنْ عَائِشَةَ رَضِيَ اَللَّهُ عَنْهَا;
«أَنَّ اَلنَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ يَقْصُرُ فِي اَلسَّفَرِ وَيُتِمُّ، وَيَصُومُ وَيُفْطِرُ»
While on a journey, the Prophet (sallallahu alayhi wa sallam) used to shorten the prayer (sometimes) and offer it completely (sometimes). Similarly, he used to observe fast (sometimes) and break it (sometimes).