‘A'isha said that Hamza b. ‘Amr al-Aslami who was greatly devoted to fasting asked the Prophet whether he should fast when on a journey, and received the reply, “Fast if you like, or break your fast if you like.” (Bukhari and Muslim.)
Hadith Referenceمشكوة المصابيح / كتاب الصوم / 2019
Hadith Gradingالألبانی:مُتَّفَقٌ عَلَيْهِ | زبیر علی زئی:متفق عليه
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «متفق عليه، رواه البخاري (1943) و مسلم (103 /1121)»