'Posterity' in the Bible

I will cast you out of My sight, as I have cast out all your brothers (relatives through Jacob), all the descendants of Ephraim.

‘Fear not, O Jacob My servant,’ says the Lord,‘Nor be dismayed or downcast, O Israel;For behold, I will save you from a distant land [of exile]And your descendants from the land of their captivity.Jacob will return and will be quiet and at ease,And no one will make him afraid.

“If this fixed order departsFrom before Me,” says the Lord,“Then the descendants of Israel also will ceaseFrom being a nation before Me forever.”