Adam Clarke on Daniel 11:23

He shall come up - From Rome, where he had been a hostage for the payment of the tax laid on his father.

Shall become strong with a small people - At first he had but few to espouse his cause when he arrived at Antioch, the people having been greatly divided by the many claimants of the crown; but being supported by Eumenes and Attalus, his few people increased, and he became strong.