Jamieson, Fausset and Brown on 2 Chronicles 12:2

2. Shishak king of Egypt came up against Jerusalem--He was the first king of the twenty-second or Bubastic Dynasty. What was the immediate cause of this invasion? Whether it was in resentment for some provocation from the king of Judah, or in pursuance of ambitious views of conquest, is not said. But the invading army was a vast horde, for Shishak brought along with his native Egyptians an immense number of foreign auxiliaries.