en_tn/rom/09/33.md

as it has been written

You can indicate that Isaiah wrote this. You can also translate it in an active form. Alternate translation: "as Isaiah the prophet wrote" (See: rc://en/ta/man/translate/figs-explicit and rc://en/ta/man/translate/figs-activepassive)

in Zion

Here Zion is a metonym that represents Israel. Alternate translation: "in Israel" (See: rc://en/ta/man/translate/figs-metonymy)

stone of stumbling and a rock of offense

These phrases mean basically the same thing and are metaphors that refer to Jesus and his death on the cross. It was as if the people stumbled over a stone because they were disgusted when they considered Jesus's death on the cross. (See: rc://en/ta/man/translate/figs-doublet and rc://en/ta/man/translate/figs-metaphor)

believes in it

Because the words "stone" and "rock" are a metaphors for a person, you may need to translate this as "believes in him." (See: rc://en/ta/man/translate/figs-metaphor)