Hadithcore
Sahih Muslim, 1121 d
sahih

This hadith has been narrated on the authority of Hisham with the same chain of transmitters that Hamza said:

I am a person much used to fasting. Should I fast during the journey? (The rest of the hadith is the same.)

وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَأَبُو كُرَيْبٍ قَالاَ حَدَّثَنَا ابْنُ نُمَيْرٍ، وَقَالَ أَبُو بَكْرٍ، حَدَّثَنَا عَبْدُ الرَّحِيمِ بْنُ سُلَيْمَانَ، كِلاَهُمَا عَنْ هِشَامٍ، بِهَذَا الإِسْنَادِ أَنَّ حَمْزَةَ، قَالَ إِنِّي رَجُلٌ أَصُومُ أَفَأَصُومُ فِي السَّفَرِ.

References2 variants
In-Book Reference
Book 13, Hadith 134
USC-MSA web (English) reference
Book 6, Hadith 2490 (deprecated numbering scheme)