Upon what details does the Hebrew author focus when speaking of Abraham?

What was his audience to gain from Abraham, Isaac, and Jacob's experience? What can we learn from it as well?

The New and Living Way | Episode 32 | Hebrews 11:8-10

By faith Abraham, when he was called, obeyed to go out unto a place which he was to receive for an inheritance; and he went out, not knowing whither he went. By faith he became a sojourner in the land of promise, as in a land not his own, dwelling in tents, with Isaac and Jacob, the heirs with him of the same promise: for he looked for the city which hath the foundations, whose builder and maker is God.