What righteous deeds qualify a believer to marry the Houris in Paradise?

Every man in Paradise will have two wives from among the Hoor al-Ayn, and the marrow of the shin of each of them will be visible from behind seventy garments. The person of the lowest status in Paradise will enter his dwelling, and his two wives from among the Hoor al-Ayn will enter upon him, saying: "All praise is due to Allah, who brought you to life for us and brought us to life for you." As for the martyr, he has six merits with Allah, among which is that "he will be married to seventy-two wives from among the Hoor al-Ayn." And whoever suppresses his rage while he is able to act upon it, Allah will call him on the Day of Resurrection before all creatures until He gives him the choice of whichever Hoor he desires.