Hebrews 11:8-12 meaning

Abraham was seen as the father of the Jewish faith, an important figure to the Pauline Author's audience. The Pauline Author uses him as an example of walking by faith as well. In Genesis 12, God tells Abraham to leave his home and go to the land that God would show him: By faith Abraham, when he was called, obeyed by going out to a place which he was to receive for an inheritance; and he went out, not knowing where he was going (v 8). 

God promises to make him a great nation and bless him. It took a lot of faith for Abraham to leave his home and follow God before knowing where he was going. However, he obeyed by going out to a place that he would eventually receive for an inheritance. 

He got to Canaan and God told him he would give the land to his descendants: By faith he lived as an alien in the land of promise, as in a foreign land, dwelling in tents with Isaac and Jacob, fellow heirs of the same promise (v 9). He lived as a stranger in this land in a rough, unsophisticated home that would not last (dwelling in tents) with his son Isaac and grandson Jacob who were also heirs of the same promise God made to Abraham. 

Abraham had faith that there was another greater city that will be built by God, a heavenly city that Christ will rule over. Although he only lived in tents, Abraham was looking for the city which has foundations, whose architect and builder is God (v 10). This faith allowed him to remain faithful in a difficult situation.

Abraham's wife, Sarah, had faith that God would fulfill His promises to them: By faith even Sarah herself received ability to conceive, even beyond the proper time of life, since she considered Him faithful who had promised (v 11). Although she was very old, she was able to conceive a son because of her faith. We know that Sarah did have doubts about her ability to have a son with a man as good as dead (Genesis 18:12) and yet even in her doubt she believed that God was faithful who had promised her a son. 

God fulfilled His promise to Abraham and Sarah—they had a son, and therefore there was born even of one man…as many descendants as the stars of the heaven in number and innumerable as the sand which is by the seashore (v 12).