The Book of Fasting
22/55. Chapter:
Mentioning the Differences reported from Mansur
Sunan an-Nasai
أَخْبَرَنَا حُمَيْدُ بْنُ مَسْعَدَةَ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنِ الْعَوَّامِ بْنِ حَوْشَبٍ، قَالَ قُلْتُ لِمُجَاهِدٍ الصَّوْمُ فِي السَّفَرِ قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَصُومُ وَيُفْطِرُ .
It was narrated that Al-'Awwam bin Hawshab said: "I said to Mujahid: 'What about fasting while traveling?' He said: 'The Messenger of Allah used to fast (sometimes) and not fast (sometimes)."'
Reference : Sunan an-Nasa'i 2292In-book reference : Book 22, Hadith 203English translation : Vol. 3, Book 22, Hadith 2294