Then the LORD said, “I will surely return to you at this time next year, and your wife Sarah will have a son!” Now Sarah was behind him, listening at the entrance to the tent.
10. I will certainly return unto thee Jerome translates its ‘I will return, life attending me:’ “Vita comite revertar.” See Vulgate , where the expression is “Revertens veniam ad to tempore illo, vita comite.” as if God, speaking in the manner of men, had said, ‘I will return if I live.’ But it would be absurd, that God, who here so magnificently proclaims his power...
These heavenly guests (being sent to confirm the promise lately made to Abraham, that he should have a son by Sarah), while they are receiving Abraham's kind entertainment, they return his kindness. He receives angels, and has angels' rewards, a gracious message from heaven, Mat 10:41. I. Care is taken that Sarah should be within hearing.
Commenting on Genesis 18:9-15
And he said,.... The same that put the question, Jehovah himself, as appears by what follows: I will certainly return unto thee according to the time of life; not by a personal appearance as now, but by the fulfilment of his promise which he had before given to Abraham, that he should have a son by Sarah, and now renews it; and this would be...