Riyad as-Salihin 1291
Salman (May Allah be pleased with him) reported:
I heard the Messenger of Allah (ﷺ) as saying, "Observing Ribat in the way of Allah for a day and a night is far better than observing Saum (fasting) for a whole month and standing in Salat (prayer) in all its nights. If a person dies (while performing this duty), he will go on receiving his reward for his meritorious deeds perpetually, and he will be saved from Al- Fattan." [Muslim] .
وعن سلمان رضي الله عنه قال‏:‏ سمعت رسول الله صلى الله عليه وسلم يقول‏:‏ ‏
"‏رباط يوم وليلة خير من صيام شهر وقيامه، وإن مات فيه أجري عليه عمله الذي كان يعمل، وأجري عليه رزقه، وأمن الفتان‏"‏ ‏(‏‏(‏رواه مسلم‏)‏‏)‏‏.‏