The ninth plague was the plague of darkness (10:21). The chief god of Egypt through the centuries, who appeared under several different names, was the sun. At this time, he was known as Amon-Re. He was supreme over all the other gods and was considered to be the ultimate source of life. The Lord showed that the sun’s light is completely under his control. God could shut it off from Egypt proper, while leaving it to shine in Goshen in the northeast part of the country (10:23; see study note on 9:1–7).