Zirr bin Hubaysh al-Asadi (may Allah have mercy on him) said that Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said to him: "What are hafadah?" I said: "A man's children." He said: "No, rather they are the in-laws (al-akhtan)."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13444