Narrated Abu Hurairah: The Prophet ﷺ said: To harbour good thoughts is a part of well-conducted worship. (This is according to Nasr's version). Abu Dawud said: Mahna' is reliable and he is from Basrah.
Related hadith on this topic
Explanation & Benefits
Shaykh Umar Farooq Saeedi
Benefits and Issues:
To harbor unnecessary bad suspicion about Muslim brothers and to base one’s dealings upon it is sinful.
(See also: Previous hadith 4917) However, it is necessary that a person himself also stays away from situations of accusation and suspicion, and does not give anyone an opportunity to think ill of him, as will be mentioned in the next hadith.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 4993