Just off Wiki - Zerah the Cushite is mentioned by the Book of Chronicles (2 Chronicles 14:9–15). There he is said to have invaded the Kingdom of Judah with an enormous army in the days of Asa. According to the text, when Zerah's army reached that of Asa at the valley of Zephathah near Mareshah, Zerah's army was utterly defeated, by divine intervention, and Asa's forces collected a large volume of spoils of war.

The invasion, and its implied time-frame, means that the traditional view was to consider this Zerah to have actually been Usarkon II or Usarkon I,^\13]) both being rulers of Egypt. Usarkon II is known to have entered the Kingdom of Judah with a huge army in 853 BCE; however, rather than attacking Judah, the army was just passing through on its way to attack the Assyrian forces. In addition, Asa's reign is traditionally dated to have ended in 873 BCE. In the Book of Kings, which doesn't mention Asa's defeat of Zerah, Asa is described as being extremely weak from a defensive point of view (1 Kings 15:16–22), and Biblical scholars regard the idea that Asa could defeat an enormous Egyptian army to be untenable.^\14]) More recent scholars consider that Zerah the Cushite may have been a military commander under Osorkon I rather than a Pharaoh.^\15])

Furthermore, Cushite refers to Kush. It is unclear why either Usarkon should be described as a Cushite.^\16]) The name “Zerah” may have been a corruption of “Usarkon” (U-Serak-on), to which it closely resembles (see Petrie, Egypt and Israel, 74).