In the life-time of the Prophet, Abu Talha did not fast because of the Jihad, but after the Prophet (ﷺ) died I never saw him without fasting except on `Id-ul-Fitr and `Id-ul-Aclha.
Sahih al-Bukhari Book 56, Hadith 44
← Previous Hadith I went to Allah's Messenger (ﷺ) while he was at Khaibar after it had fallen in the Muslims' hands. I said, "O Allah's Messenger (ﷺ)! Give me a share (from the land of Khaibar)."

One of the sons of Sa'id bin Al-'As said, "O Allah's Messenger (ﷺ)! Do not give him a share." I said, "This is the murderer of Ibn Qauqal." The son of Said bin Al-As said, "Strange! A Wabr (i.e. guinea pig) who has come down to us from the mountain of Qaduim (i.e. grazing place of sheep) blames me for killing a Muslim who was given superiority by Allah because of me, and Allah did not disgrace me at his hands (i.e. was not killed as an infidel)." (The sub-narrator said "I do not know whether the Prophet (ﷺ) gave him a share or not.")

Sahih al-Bukhari Book 56, Hadith 43 Next Hadith → Allah's Messenger (ﷺ) said, "Five are regarded as martyrs: They are those who die because of plague, Abdominal disease, drowning or a falling building etc., and the martyrs in Allah's Cause."

Sahih al-Bukhari Book 56, Hadith 45