Genesis 17:15

“God said to Abraham, ‘As for Sarai your wife, you shall not call her name Sarai, but Sarah shall be her name’” (Gen. 17:15).

Our excursus on baptism now ended, we turn back to the book of Genesis and pick up the storyline in 17:15. Having promised to provide an heir for Abraham and afterwards imposing circumcision on the patriarch and his family to “cut” them out of the world (vv. 1–14), the Lord now renames Sarai.

Many scholars try to discern significance in the new name itself. Several possibilities are offered, but it seems likely that Sarah is simply a spelling variation of the name Sarai, much like we often find in English (for example, Katherine or Catherine). Yet even though the two names do not differ in meaning, the change in itself is not to be taken lightly. God has a purpose in renaming Abraham’s wife.

The names Sarah and Sarai both mean “princess,” and this is no coincidence. Abraham will father a nation of kings, but so far it has not been explicitly clear who the mother of this great people will be. Yet some clues have intimated Sarah must bear the promised son. For instance, the plagues on Pharaoh and his house in 12:10–20 after he takes Sarah for a wife strongly imply that God’s word to Abraham will not be fulfilled apart from her. However, no direct statement from the Almighty has yet confirmed this. If we knew nothing of the biblical narrative apart from what we have thus far read in Genesis, we might even think the promise regarding Ishmael (16:11–12) pointed to him as the favored son.

We will have to wait until 17:16 for the unquestionable affirmation that Sarah will bear the chosen child. But Sarah’s name-change ought to remind us of her royal dignity, and thus it offers more indirect proof that Abraham’s progeny will come from her. After all, who is more fit than a princess to birth a kingly nation?

In the end, Sarah’s new name is an especially clear revelation of the Lord’s grace. She and Abraham have sinned in producing a son by Hagar (chap. 16), but Yahweh maintains His goodness toward them nonetheless. As John Calvin comments, “The gratuitous kindness of God shines the more clearly, because, although men impede the course of it by obstacles of their own, it nevertheless comes to them.”

Coram Deo

While our sin can cause the Lord’s discipline to come upon us, it cannot finally prevent His kindness from resting on us, if indeed He has mercifully determined to save us. The elect of God are not to take this for granted; they instead seek to please Him by discerning His will, repenting of sin, and following His commandments. Do you feel you have done something to block the Lord’s kindness? Turn to Him in repentance and obey His will revealed in Scripture.

For Further Study