Bulugh al-Maram, Book 5, Hadith 695 (English) ⓘ

Hamzah bin ’Amro Al-Aslami (RAA) narrated, ‘I said to the Messenger of Allah ‘O Messenger of Allah! I find within me the strength to fast while traveling. Would there be any blame upon me if I were to do so?’ The Messenger of Allah said to him, "It is a concession from Allah. Whoever takes it has done well. Whoever likes to fast, there is no blame upon him."Related by Muslim.

وَعَنْ حَمْزَةَ بْنِ عَمْرٍو الْأَسْلَمِيِّ رِضَى اَللَّهُ عَنْهُ; أَنَّهُ قَالَ: { يَا رَسُولَ اَللَّهِ! أَجِدُ بِي قُوَّةً عَلَى اَلصِّيَامِ فِي اَلسَّفَرِ, فَهَلْ عَلَيَّ جُنَاحٌ? فَقَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏- " هِيَ رُخْصَةٌ مِنَ اَللَّهِ, فَمَنْ أَخَذَ بِهَا فَحَسَنٌ, وَمَنْ أَحَبَّ أَنْ يَصُومَ فَلَا جُنَاحَ عَلَيْهِ " } رَوَاهُ مُسْلِمٌ 1‏.‏ ‏1 ‏- صحيح.‏ رواه مسلم ( 1121 )‏ ( 107 )‏.‏