Sahih al-Bukhari 908
صحيح البخاري#908SahihNarrated Abu Huraira:heard Allah's Messenger (ﷺ) saying, "If the prayer is started do not run for it but just walk for it calmly and pray whatever you get, and complete whatever is missed
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 11:32