C. F. Keil and Franz Delitzsch on 2 Chronicles 26:7

2Ch 26:7

As against the Philistines, so also against the Arabians, who dwelt in Gur-baal, God helped him, and against the Maanites, so that he overcame them and made them tributary. Gur-baal occurs only here, and its position is unknown. According to the Targum, the city Gerar is supposed to be intended; Lxx translate ἐπὶ τῆς Πέτρας, having probably had the capital city of the Edomites, Petra, in their thoughts. The מעוּנים are the inhabitants of Maan; see on 1Ch 4:41.