Some people were disputing in her presence on the day of Arafah about whether the Messenger of Allah ﷺ was fasting. Some said, "He is fasting," while others said, "He is not fasting." So she sent him a cup of milk while he was standing on his camel, and he drank it.
أن ناسا تماروا عندها يوم عرفة في صيام رسول الله ﷺ، فقال بعضهم: هو صائم. وقال بعضهم: ليس بصائم، فأرسلت إليه بقدح لبن وهو واقف على بعيره فشرب.
Malik narrated it in Hajj (132), from Abu Nadr, the freedman of Umar bin Ubaydullah, from Umayr, the freedman of Abdullah bin Abbas, from Umm Fadl, and he related it.Bukhari narrated it in Hajj (1661), and Muslim in Fasting (1123:110), both of them by way of Malik, with the same chain, similarly.