Full Sharh — Sahih Muslim 2626
وَحَدَّثَنَا أَبُو الرَّبِيعِ الزَّهْرَانِيُّ، حَدَّثَنَا حَمَّادٌ، - وَهُوَ ابْنُ زَيْدٍ - حَدَّثَنَا هِشَامٌ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، - رضى الله عنها - أَنَّ حَمْزَةَ بْنَ عَمْرٍو الأَسْلَمِيَّ، سَأَلَ رَسُولَ اللَّهِ صلى الله عليه وسلم فَقَالَ يَا رَسُولَ اللَّهِ إِنِّي رَجُلٌ أَسْرُدُ الصَّوْمَ . أَفَأَصُومُ فِي السَّفَرِ قَالَ " صُمْ إِنْ شِئْتَ وَأَ��ْطِرْ إِنْ شِئْتَ " .
English Translation
A'isha (Allah be pleased with her) reported that Hamza b. Amr al-Aslami asked the Messenger of Allah (ﷺ) thus:Messenger of Allah, I am a person devoted much to fasting. Should I fast during the journey? He (the Holy Prophet) said: Fast if you like and break it if you like
Source
Sahih Muslim(صحيح مسلم)
The Book of Fasting
Hadith Number
2626