‘Muhammad bin Munkadir says that’ Salman al-Farsi (may Allah be pleased with him) passed by Shurahbil bin Simt, who was at his «مرابط» (a place of guarding on the frontier), and staying there was burdensome for him and his companions. Salman al-Farsi (may Allah be pleased with him) said: Ibn Simt? Shall I not narrate to you the hadith which I heard from the Messenger of Allah (peace and blessings of Allah be upon him)? He said: Why not. Salman (may Allah be pleased with him) said: I heard the Messenger of Allah (peace and blessings of Allah be upon him) say:“Guarding for one day in the way of Allah is better than fasting for a month and standing in prayer at night. Sometimes he said «أفضل» instead of «خير» (is better). And whoever dies in this state will be safe from the punishment of the grave, and his deeds will continue to increase until the Day of Resurrection.”1. Imam Tirmidhi says:
This hadith is Hasan Sahih.