I’ve jumped passed it. This chapter is attributed to the Priestly source. It is written in a very ponderous, disciplined way and once again finds Abraham doubting (and laughing at) the promise. However it is also the moment when  Abram & Sarai become  Abraham and Sarah – and that is how they are known from now onwards; introduces a covenant relationship and a mark of belonging to this distinctive community through circumcision. 

Genesis 18 comes from the source known as the Yahwahist. It has a far more fluent storytelling style that is ‘“an accomplished work of epic art”: it expects  of the reader a willingness to be told a story. i.e the open-mindedness which can share in the most incidental details and understand latent subtleties and intimations.” Gerhard von Rad, Genesis, 1961.

18:1 YHWH or Angels?  singular Lord, plural three men, singular “My Lord,…” (v3)

a Revelatory encounter. 

18:2-8 The perils of welcome created an intricate ritual. Greeting – offer of shelter – acceptance – offer of food – acceptance – more food available than suggested – acceptance – served by host – creates debt – and ensure no threat to safety. 

urgency of the narrative – saw- ran – bow – brought – wash – rest – refresh – hastened – make ready – knead – make – ran – took – gave – hastened – prepare  took – set it before – stood – ate.

18:9-15 “Where is your wife, Sarah?” impolite!

“your wife Sarah shall have a son” unlike Hagar, the messenger does not speak directly to her.

Sarah laughs (cf 17:7) 

“this radical gospel requires shattering and discontinuity. Abrahm and Sarah have by this time becomes accustomed to their barrenness. they are resigned to their closed future. They have accepted their hopelessness as “normal”. the gospel promise does not meet them in receptive hopefulness but in resistant hopelessness.” Brueggemann

The call of God is nonsensical!

The Lord said to Abraham. “Why did Sarah laugh? … Is anything too wonderful for the Lord?

“I did not laugh”

“Oh yes, you did laugh”

“The laughter of disbelief seems to refute the invitation implicit in the question. Abraham and sarah’s world of possibility has been assaulted. But they have beaten off the attack. the story leaves them thinking their presumed world is still intact”

But not everything depends on their answer. The resolve of God to open a future by a new heir does not depend on the readiness of Abraham and Sarah to accept it” Bruggemann p 160. 

cf Elizabeth, Mary, 

Mk 10:27 “With humans it is impossible, but not with God for all things are possible with God.” 

Matthew 17:20 Nothing will be impossible for you. 

18:16 to set them on their way …