Abu Talha used to fast frequently during the lifetime of the Messenger of Allah ﷺ. After the Prophet ﷺ passed away, he would not break his fast except while traveling or when ill.
حدثنا ابن أبي عدي عن حميد
كان أبو طلحة يكثر الصوم على عهد رسول الله ﷺ فلما مات النبي ﷺ كان لا يفطر إلا في سفر أو مرض
No references are available.
Its isnad is sahih. Bukhari narrated something similar in Fath al-Bari 6/42, no. 2828, in the Book of Jihad, chapter on one who chooses fighting over fasting.