al-Mufadl bin Fadala bin 'Ubaid المفضل بن فضالة بن عبيد بن ثمامة · The Book of Fasting

"We were traveling in Ramadan and among us were some who were fasting and some who were not. Those who were fasting did not criticize those who were not, and those who were not fasting did not criticize those who were."