#Now Yahweh appeared

Here "Now" introduces Yahweh into this part of the story.

#appeared to him

"appeared to Isaac"

#Do not go down to Egypt

It was common to speak of leaving the promised land as "going down" to somewhere else. (See: [[:en:ta:vol1:translate:figs_idiom]])

#for to you and to your descendants, I will give all these lands

"for I will give all these lands to you and your descendants"

#I will fulfill the oath that I swore to Abraham your father

"I will do what I promised to Abraham your father that I would do"