And the Lord said unto Abraham
This discovers who the person was that had been conversing with Abraham, that he was a divine Person, as appears by his name "Jehovah", as well as by his knowledge of Sarah's behaviour; he did not turn himself to her, that it might be more manifest that it was not upon the sight of her he judged she laughed, but from his own omniscience; and he chose rather to speak to her husband than to her, appearing as a stranger, and that he might reprove her: wherefore did Sarah laugh, saying, shall I of a surety bear a child,
which am old?
suggesting there was no reason for it, and signifying his displeasure and indignation at it.