#When Abram was ninety-nine years old

nine years old** - 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.

#God Almighty

"the all-powerful God" or "the God who has all power"

#Walk before me

Walking is a metaphor for living, and "before me" or "in my presence" here is a metaphor for obedience. AT: "Live the way I want you to" or "Obey me." (See: [[:en:ta:vol1:translate:figs_metaphor]])

#Then I will confirm

"If you do this, then I will confirm"

#I will confirm my covenant

"I will give my covenant" or "I will make my covenant"

#covenant

In this covenant God promises to bless Abram, but he also requires Abram to obey him.

#multiply you exceedingly

"greatly increase the number of your descendants" or "give you very many descendants" (See: [[:en:ta:vol1:translate:figs_idiom]])