ה֣וֹן עָ֭שִׁיר קִרְיַ֣ת עֻזּ֑וֹ וּכְחוֹמָ֥ה נִ֝שְׂגָּבָ֗ה בְּמַשְׂכִּיתֽוֹ׃
富足人的財物是他的堅固城，在他鋪石的內室裡，如同高聳的城牆。
Rashi
and like a strong wall his wealth is to him in his chambers. Since the house is paved with a floor of stones that cover the earth, it is called אבן משכית, a covering stone.