After Jerusalem was destroyed, the Edomites captured fleeing Jews and gave them to Babylon. The book of Obadiah is about God's judgment against the Edomites for harming his people. The book was intended to give comfort to the people of Judah in exile.
Translators may decide to translate this traditional title, "The Book of Obadiah," in a way that is clearer to the readers. Translators may decide to call it, "The Sayings of Obadiah." (See: [[rc://en/ta/man/translate/translate-names]])
Obadiah referred to Edom as Israel's brother. This is because the Edomites were descendants of Esau, and the Israelites were descendants of Jacob. Jacob and Esau were brothers. This made Edom's betrayal of Israel much worse.
Obadiah spoke a lot about "pride" in his book. When Obadiah spoke about the "pride" of Edom, he meant that the Edomites thought they were more powerful than Yahweh and that he would not or was not able to punish them. (See: rc://en/tw/dict/bible/other/proud)