TSK · Genesis 17:24

So Abram left, just as the LORD had told him to do, and Lot went with him.(Now Abram was 75 years old when he departed from Haran.)

Then Abraham bowed down with his face to the ground and laughed as he said to himself,“Can a son be born to a man who is a hundred years old? Can Sarah bear a child at the age of ninety?”

(Now Abraham was a hundred years old when his son Isaac was born to him.)

Without being weak in faith, he considered his own body as dead(because he was about one hundred years old) and the deadness of Sarah’s womb.