Jami` at-Tirmidhi 714
جامع الترمذي#714Da'ifMa'mar bin Abi Huyaiyah narrated that:he asked Ibn Al-Musaiyab about fasting on a journey, so he narrated to him that Umar bin Al-Khattab said: "We fought in two battles along with the Messenger of Allah during Ramadan; the Day of Badr, and the Conquest (of Makkah), so we broke our fast during them
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirDaif Isnaad
Al-AlbaniDaif Isnaad
Zubair Ali ZaiDaif
In-book reference: 8:33