What does Daniel 11:9 mean?

This passage contains a prophecy given to Daniel in 536 BC (Daniel 10:1; 11:2). History has proven the accuracy of the predictions. Those included the rise and fall of Alexander the Great, including the division of his territories, and then described conflicts between two successor nations (Daniel 11:3–6). Among the events included in this prophecy is the 246 BC invasion of the Seleucid Empire by Egypt under Ptolemy III Euergetes. This was launched to avenge the death of Euergetes's sister, Berenice, and it resulted in the looting of tremendous wealth. It also allowed Egypt to confiscate religious idols on their way back home (Daniel 11:7–8).

Here, it is noted that the king of the north—Seleucus II Callinicus—was able to reach Egypt, in the south, but had to return empty-handed. Because Euergetes returned with his spoils, rather than establishing control, it was not difficult for Seleucus to regain territory. But infighting and chaos made it impossible to mount a realistic counterattack against Egypt. For many years, the Seleucid Empire wallowed in conspiracies and squabbling.

Eventually, the descendants of Callinicus would regain enough strength to push back against Egypt (Daniel 10:10).