Sahih Muslim 1913a

Abdullah ibn Abd al-Rahman ibn Bahram al-Darimi narrated to us: Abu al-Walid al-Tayalisi narrated to us: Layth, meaning Ibn Sad, narrated to us, from Ayyub ibn Musa, from Mak-hul, from Shurahbil ibn al-Simt, from Salman, who said: I heard the Messenger of Allah say: “Guarding the frontier for a day and a night is better than fasting for a month and standing in prayer during it. If a person dies, the deeds he used to perform will continue to be recorded for him, his provision will continue to reach him, and he will be protected from the trial of the grave.”