On several occasions in Genesis 17 and 18 the Lord declares a specific time that he will come and Sarah will conceive and have a son. “At this set time” (Genesis 17: 21), “According to the time of life” (Genesis 18: 10), and “At the time appointed according to the time of life” (Genesis 18: 14). The time of life is not referring to the natural time of a woman to have children but to the appointed time of life decreed by the counsel of God.

As Sarah stands a symbol of the church, this ‘time’ is very significant. Her presence in the tent was called for and God spoke to her indirectly through her husband, as he does to the church through Christ, and gave her the promise. We all know that “to Abraham and his seed were the promises made” and that “He saith not and to seeds as of many; but as of one, and to thy seed which is Christ.” (Galatians 3: 16). But on this occasion, Sarah’s presence was called for to hear this promise in a little different light. It was not so much to her that the promise was made but in her to be manifested. Paul spoke of his own experience of grace as God revealing his Son in him and so declared this mystery to the Gentiles summing up the revelation as “Christ in you the hope of glory” (Galatians 1: 16, Colossians 1: 27).

It was not the promise of God to produce an heir that caused her to laugh in doubt, but it was the idea that the heir must be produced in her. Sarah stood in the door of her tent and tried to imagine herself in her present condition standing naked before her husband and being able to stir a passion in him to produce one of her own. She laughed at the thought of it. “She laughed saying, after I am waxed old shall I have pleasure my lord being old also?” (Genesis 18: 12).

To produce this promised heir she must willingly and lovingly receive the seed of he husband. This ‘time’ is not when she is young and beautiful and full of passion but when she in herself is convinced of God that she is no longer desired at all. Dead, repulsive, and unable is the ‘time’ when God sews his seed.

The experience of grace is beyond what the sinner can imagine. Ruined and helpless, unclean and filthy he cannot imagine the Lord desiring him. As he must of God be convinced of sin; he must of God be convinced of love. The word of God is of no benefit to a man until the Holy Spirit of God embraces him with the gospel and puts the blessed seed in him.

Listen to how Peter describes the event – “Being born again, not of corruptible seed, but of incorruptible, by the word of God which liveth and abideth forever (pictures the bride). For all flesh is grass and all the glory of man as the flower of the grass. The grass withereth and the flower thereof falleth away; but the word of the Lord endureth forever. And this is the word which by the gospel is preached unto you.”