It is narrated from Sayyiduna al-Irbad bin Sariyah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Every deed of a person is cut off when he dies, except for the one guarding the frontier (ribat) in the way of Allah; his deeds keep growing and his provision keeps reaching him until the Day of Resurrection."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 15732