AbdulLaah bn Mas'ood (radhiyal Laahu 'anh) relates:
The messenger of Allaah (sallal Laahu 'alayhi wasallam) said:
"You do continuously fall into destructive sins but when you observe the Subh prayer, it washes them away.
Thereafter, you do continuously fall into destructive sins but when you observe the Dhuhr prayer, it washes them away.
Thereafter, you do continuously fall into destructive sins but when you observe the 'Asr prayer, it washes them away.
Thereafter, you do continuously fall into destructive sins but when you observe the Maghrib prayer, it washes them away.
Thereafter, you do continuously fall into destructive sins but when you observe the 'Ishaa prayer, it washes them away and by so doing, you go to bed while no sins are being recorded against you."
- Tabaraanee, Saheeh Targheeb #357.