Abu 'Amir al-'Aqdi عبد الملك بن عمرو القيسي أبو عامر العقدي · The Book of Fasting

"we had been travelijng for as long as Allah willed, then we came to the Messenger of Allah and he was eating. He said: 'Come and eat.' I said: 'I am fasting.' The Messenger of Allah said: 'I will tell you about fasting. Allah has waived fasting and half of the prayer for the traveler."'