TSK · Genesis 21:5

And Abram was fourscore and six years old, when Hagar bare Ishmael to Abram.

Then Abraham fell upon his face, and laughed, and said in his heart, Shall a child be born unto him that is a hundred years old? and shall Sarah, that is ninety years old, bear?

And after that came forth his brother, and his hand had hold on Esau's heel; and his name was called Jacob: and Isaac was threescore years old when she bare them.

And without being weakened in faith he considered his own body now as good as dead (he being about a hundred years old), and the deadness of Sarah's womb;