It is narrated from Hazrat Abu Umamah (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: Four types of people continue to receive reward even after their death: (1) The one who guards the Islamic borders in the way of Allah, (2) The one who performs a good deed whose effect continues, (3) The person who gives ongoing charity (sadaqah jariyah), (4) The person who leaves behind righteous children who pray for him.