And they said unto him, Where is Sarah thy wife? And he said, Behold, in the tent.

Wesley's Notes

18:9 Where is Sarah thy wife? - By naming her, they gave intimation to Abraham, that tho' they seemed strangers, yet they well knew him and his family: by enquiring after her, they shewed a kind concern for the family of one, whom they found respectful to them. And by speaking of her, she over - hearing it, they drew her to listen to what was farther to be said.

Jamieson-Fausset-Brown Bible Commentary

Ge 18:9-15. Reproof of Sarah. An inquiry about his wife, so surprising in strangers, the subject of conversation, and the fulfilment of the fondly cherished promise within a specified time, showed Abraham that he had been entertaining more than ordinary travellers (Heb 13:2).

Matthew Henry's Concise Commentary

18:9-15 Where is Sarah thy wife? was asked. Note the answer, In the tent. Just at hand, in her proper place, occupied in her household concerns. There is nothing got by gadding. Those are most likely to receive comfort from God and his promises, who are in their proper place, and in the way of their duty, Lu 2:8. We are slow of heart to believe, and need line upon line to the same purport. The blessings others have from common providence, believers have from the Divine promise, which makes them very sweet, and very sure. The spiritual seed of Abraham owe their life, and joy, and hope, and all, to the promise. Sarah thinks this too good news to be true; she laughed, and therefore cannot as yet find in her heart to believe it. Sarah laughed. We might not have thought there was a difference between Sarah's laughter and Abraham's, ch. 17:17; but He who searches the heart, saw that the one sprung from unbelief, and the other from faith. She denied that she had laughed. One sin commonly brings in another, and it is not likely we shall strictly keep to truth, when we question the Divine truth. But whom the Lord loves he will rebuke, convict, silence, and bring to repentance, and if they sin before him.