Adam Clarke on Genesis 23:2

Sarah died in Kirjath-arba - Literally in the city of the four. Some suppose this place was called the city of the four because it was the burial place of Adam, Abraham, Isaac, and Jacob; others, because according to the opinion of the rabbins, Eve was buried there. with Sarah, Rebekah, and Leah. But it seems evidently to have had its name from a Canaanite, one of the Anakim, probably called Arba (for the text, Jos 14:14, does not actually say this was his name), who was the chief of the four brothers who dwelt there; the names of the others being Sheshai, Ahiman, and Talmai. See Jdg 1:10. These three were destroyed by the tribe of Judah; probably the other had been previously dead.

Abraham came to mourn for Sarah - From Gen 22:19 of the preceding chapter it appears that Abraham had settled at Beer-sheba; and here we find that Sarah died at Hebron, which was about twenty-four miles distant from Beersheba. For the convenience of feeding his numerous flocks, Abraham had probably several places of temporary residence, and particularly one at Beer-sheba, and another at Hebron; and it is likely that while he sojourned at Beersheba, Sarah died at Hebron; and his coming to mourn and weep for her signifies his coming from the former to the latter place on the news of her death.