Kejadian 17:19

17:19 God said, “No, Sarah your wife is going to bear you a son, and you will name him Isaac. ¹  I will confirm my covenant with him as a perpetual ²  covenant for his descendants after him.

Roma 9:9

9:9 For this is what the promise declared: ³  “About a year from now ⁴  I will return and Sarah will have a son.” ⁵ 

Galatia 4:23

4:23 But one, the son by the slave woman, was born by natural descent, ⁶  while the other, the son by the free woman, was born through the promise.

[17:19]  ¹ tn Heb “will call his name Isaac.” The name means “he laughs,” or perhaps “may he laugh” (see the note on the word “laughed” in v. 17).

[17:19]  ² tn Or “as an eternal.”

[9:9]  ³ tn Grk “For this is the word of promise.”

[9:9]  ⁴ tn Grk “About this time I will return.” Since this refers to the time when the promised child would be born, it would be approximately a year later.

[9:9]  ⁵ sn A quotation from Gen 18:10, 14.

[4:23]  ⁶ tn Grk “born according to the flesh”; BDAG 916 s.v. σάρξ 4 has “Of natural descent τὰ τέκνα τῆς σαρκός children by natural descent Ro 9:8 (opp. τὰ τέκνα τῆς ἐπαγγελίας). ὁ μὲν ἐκ τῆς παιδίσκης κατὰ σάρκα γεγέννηται Gal 4:23; cp. vs. 29.”