Hadith
أَخْبَرَنَا عَمْرُو بْنُ مَنْصُورٍ، قَالَ حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، قَالَ حَدَّثَنَا اللَّيْثُ، قَالَ حَدَّثَنِي أَيُّوبُ بْنُ مُوسَى، عَنْ مَكْحُولٍ، عَنْ شُرَحْبِيلَ بْنِ السِّمْطِ، عَنْ سَلْمَانَ، قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " مَنْ رَابَطَ فِي سَبِيلِ اللَّهِ يَوْمًا وَلَيْلَةً كَانَتْ لَهُ كَصِيَامِ شَهْرٍ وَقِيَامِهِ فَإِنْ مَاتَ جَرَى عَلَيْهِ عَمَلُهُ الَّذِي كَانَ يَعْمَلُ وَأَمِنَ الْفَتَّانَ وَأُجْرِيَ عَلَيْهِ رِزْقُهُ " .
It was narrated that Salman said:"I heard the Messenger of Allah (ﷺ) say: 'Whoever guards Ribat (the frontier) in the cause of Allah for one day and one night, he will have (a reward) like that of fasting and praying Qiyam for a month. If he dies he will continue to receive reward for what he did, and he will be kept safe from Al-Fattan, and he will be given provision
Sahih · Abu Ghuddah
Sunan an-Nasa'i 3168 ·Book 25, Hadith 84·Also available on sunnah.com·