'Ancestor's' in the Bible

A man of God came to Eli and said to him, "This is what the Lord says: 'Did I not plainly reveal myself to your ancestor's house when they were in Egypt in the house of Pharaoh?

I chose your ancestor from all the tribes of Israel to be my priest, to offer sacrifice on my altar, to burn incense, and to bear the ephod before me. I gave to your ancestor's house all the fire offerings made by the Israelites.

Therefore the Lord, the God of Israel, says, 'I really did say that your house and your ancestor's house would serve me forever.' But now the Lord says, 'May it never be! For I will honor those who honor me, but those who despise me will be cursed!