"And Allah has made for you mates from yourselves," meaning: wives. "And He has made for you, from your mates, sons and grandsons (hafadatan)." The interpretation of al-Hasan: The hafada are the servants; he means by that one's children and children's children. It is said: they are sons and servants.
Muhammad says: The root of al-hafd is service and work. From it, it is said in the Qunut: "And toward You we hasten and serve (nahfidu)," meaning: we act in obedience to You.