Some translations set each line of poetry farther to the right than the rest of the text to make it easier to read. The ULB does this with verses 25-29 and 33 of this chapter. Paul quotes all of these words from the Old Testament.
Paul uses the word "flesh" in this chapter only to refer to Israelites, people physically descending from Abraham through Jacob, whom God named Israel. (See: [[rc://en/tw/dict/bible/kt/flesh]])
In other chapters, Paul uses the word "brother" to mean fellow Christians. However, in this chapter, he uses "my brothers" to mean his kinsmen the Israelites.
Paul refers to those who believe in Jesus as "children of God" and "children of the promise."
In verses 6-21 Paul speaks of "the promises of God" and says that it is because of God's choice that some people will receive those promises and others will not. Some take this to indicate that God has, from before the foundation of the world, chosen his own people to be eternally saved. Christians have different views on what the Bible teaches on this subject. So translators need to take extra care when translating this chapter, especially with regards to elements of causation. (See: [[rc://en/tw/dict/bible/kt/predestine]] and [[rc://en/tw/dict/bible/kt/save]])
Paul explains that while some Gentiles accepted Jesus as their savior by believing in him, most Jews were trying to earn their salvation and so rejected Jesus. Paul, quoting the Old Testament, describes Jesus as a stone that the Jews stumble over when walking. This "stone of stumbling" causes them to "fall." (See: [[rc://en/ta/man/translate/figs-metaphor]])
Paul uses the word "Israel" in this verse with two different meanings. The first "Israel" means the physical descendants of Abraham through Jacob. The second "Israel" means those who are God's people through faith. The UDB reflects this.