Genesis 18:9-15

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

An enquiry about his wife, so surprising in strangers, the subject of conversation, and the announced fulfillment of the fondly cherished promise at a specified time, showed Abraham that he had been entertaining more than ordinary travelers (Hebrews 13:2).

Verse 10 I will certainly return unto thee according to the time of life [Hebre k ` t (H6256) Verse 10. I will certainly return unto thee according to the time of life, [Hebrew, kaa`eet (H6256) chayaah (H2416); with the reviving year] - i:e., the coming spring, when the winter shall be past and nature revives (Gesenius). [Septuagint, kata ton kairon touton eis hooras (cf. 2 Kings 4:16-17).]

Sarah heard it in the tent door, which was behind him. The women's apartment is in the back of the tent, divided by a thin partition from the men's. [The Septuagint has: ousa opisthen autos-she being behind him.]

Verse 12. Laughed within herself. Long delay seems to have weakened her faith. Sarah treated the announcement as incredible, and, when taxed with the silent sneer, added falsehood to distrust. It was an aggravated offence (Acts 5:4), and nothing but grace saved her (Romans 9:18). She had not that faith which was accounted to Abraham for righteousness; because in the circumstance of her incredulous smile, she was following the dictates of her natural reason only, not the word of God, whose power she limited by the results of her own observation and experience. It was important that she should be brought to believe everything He promised, without reasoning concerning its apparent impossibility, from a full conviction of His ability to perform it, because He is God; and our keeping this in view will help us to understand the way in which she was dealt with. Being behind him, she thought that her private manifestation of incredulity would not be known; because she was not yet cognizant of the fact that the speaker was the Lord. But it was necessary that her unbelieving sneer should be exposed by Omniscience, in order that she might be brought to a full conviction of the divine character of the Visitor, and thereby be led to the exercise of a believing trust in the fulfillment of the promise. Hence, the speaker repeated that she did laugh; thus leading her, as our Lord did Nathanael (John 1:48), to perceive that He was a Divine Person. The first part of their business being executed, the men rose to leave. The supernatural birth of Isaac was intended as a typical preparation-to present one prominent aspect of the many-sided mystery of the incarnation.