Yusuf bin 'Isa bin Dinar يوسف بن عيسى بن دينار الزهري · The Book on Fasting

the Messenger of Allah said: "Do not let the Adhan of Bilal prevent you from your Sahar, nor the drawn out Fajr, but the Fajr that spreads on the horizon."

"Some cavalry man of the Messenger of Allah came galloping upon us, so I came to the Messenger of Allah and found him having lunch. He said: "Come and eat." I said: 'I am fasting.' So he said: 'Come and I will narrate to you about the fast - or fasting. Indeed Allah Most High lifted (the fast and) half of the Salat from the traveler, and (He lifted) the fast - or fasting - from the pregnant person, or…