From among the four names of the city of Hebron, the Torah chooses the name Kiryat Arba when referring to the burial place of Sarah. The Sages explain that this name contains an allusion to the uniqueness of the place.

“Sarah died in Kiryat Arba” (Genesis 23:2). This location was called by four names: Eshkol, Mamre, Kiryat Arba, and Hebron. Why did the verse call it Kiryat Arba [literally, Town of the Four]? Because four righteous men resided there: Aner, Eshkol, Mamre, and Abraham, and four righteous men were circumcised there: Abraham, Aner, Eshkol, and Mamre. Alternatively, the verse refers to it as Kiryat Arba because four patriarchs of the world were ultimately buried there: Adam the first man, Abraham, Isaac, and Jacob. Alternatively, the verse refers to it as Kiryat Arba because ultimately four matriarchs were buried there: Eve, Sarah, Rebecca, and Leah. (Bereshit Rabba 58)