It was narrated from Hamzah bin ‘Amr that he said to the Messenger of Allah صلی اللہ علیہ وآلہ وسلم “I feel able to fast while traveling; is there any sin on me?” He said: “It is a concession from Allah, the Mighty and Sublime, so whoever accepts it has done well, and whoever wants to fast, there is no sin on him.” (Sahih)