TSK · Genesis 21:5

(Now Abram was 86 years old when Hagar gave birth to Ishmael.)

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?”

When his brother came out with his hand clutching Esau’s heel, they named him Jacob. Isaac was sixty years old when they were born.

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.