'Ancestors' in the Bible

""The LORD also announces to you: "The LORD will himself build a house for you. When your life is complete and you go to join your ancestors, I will raise up your offspring after you, who will come forth from your body, and I will fortify his kingdom.

But the woman from Tekoa told the king, "Your majesty, let any guilt for this be on me and on my ancestors' household, and not on my king or his throne!"

When Ahithophel saw that his advice [was] not followed, he saddled the donkey, and he set out and went up to his house in his city. {After he set his house in order}, he hanged himself, and he died and was buried in the tomb of his ancestors.