It is not Heaven. You know that, right? From studying the Bible which is God’s Word.
AND you'll notice Jesus speaks of Abraham being in "the kingdom of heaven" or "the kingdom of God":
Matthew 8:11
I tell you, many will come from east and west and will eat with Abraham and Isaac and Jacob in the kingdom of heaven.
Luke 13:28
There will be weeping and gnashing of teeth when you see Abraham and Isaac and Jacob and all the prophets in the kingdom of God, and you yourselves thrown out.
Context: we were talking about "God's saving plan". and in this very profound teaching parable, Lazarus the poor Jew is in a place of blessedness: he is saved from Hell. And the rich man, Dives, is not.