The Danger of Over-Suspicion
ʿAbdullāh b. Masʿūd – Allāh be pleased with him – said:
The victim of theft might continue to suspect and conjecture [about who stole from him] until he becomes worse [in sin] than the thief.
Al-Bukhārī, Al-Adab Al-Mufrad no. 1289. Its chain of transmission was graded ṣaḥīḥ by Al-Albānī in Ṣaḥīḥ Al-Adab Al-Mufrad no.974.
Also read
Related sayings.
Ibn Masud on three things that set a person on the path of being the most devout, careful and richest of people.
Ibn Masud on what truthfulness and lying lead to.