مُسْنَدُ أَحْمَدَ
Musnad Ahmad 1456
Musnad Abu Ishaq Sa'd bin Abi Waqqas
Isma"eel bin Muhammad bin Sa"d bin Abi Waqqas narrated, from his father, that his grandfather said: The Messenger of Allah (ﷺ) instructed me to call out during the days of Mina: “These are days of eating and drinking, so no one should fast during them" - i.e., the days of at-tashreeq.
Musnad Ahmad 1456Sahih because of corroborating evidence]