al-Qasim bin Zakaria bin Yahya القاسم بن زكريا بن يحيى البغدادي · The Book of Fasting

"We were with the Messenger of Allah on a journey, and some of us were fasting and some of us were not. We made a stop on a hot day and looked for shade. Those who were fasting fell to the ground, but those who were not fasting got up and watered the animals. The Messenger of Allah said: 'Those who were not fasting today have taken the reward.""

"There is no fast for the one who does not intend to fast before dawn." Malik bin Anas narrated it in Mursla from.