This phrase is used here to mark the beginning of a new part of the story. If your language has a way for doing this, you could consider using it here.
"promise me in the name of God" or "promise me with God as your witness"
## that you will not deal falsely with me ##
"that you will not lie to me"
## covenant faithfulness ##
This faithfulness because the two men had made a covenant with each other. It can be translated as "faithfulness because of our covenant" or "faithfulness" or "loyalty."
## to the land ##
"to the people of the land
## I swear ##
"I swear to show you the kindness you have shown to me." (See: [[rc://en/ta/man/translate/figs-ellipsis]])