Jamieson, Fausset & Brown, on Gen 17:17

“Abraham fell upon his face, and laughed, saying in his heart: Shall a son, thinkest thou, be born to him that is a hundred years old? and shall Sara that is ninety years old bring forth?”

“Abraham fell upon his face, and laughed--It was not the sneer of unbelief, but a smile of delight at the improbability of the event (Rom 4:20).”

Imported from an open dataset — not yet checked against the printed edition.