And when he hath taken away the multitude, his heart shall be lifted up; and he shall cast down many ten thousands: but he shall not be strengthened by it.

Wesley's Notes

11:12 His heart shall be lifted up - He might have recovered all, but he grew proud of his victory, and returned again to his luxury.

Jamieson-Fausset-Brown Bible Commentary

12. when he hath taken away-that is, subdued "the multitude" of Antiochus.

heart . lifted up-instead of following up his victory by making himself master of the whole of Syria, as he might, he made peace with Antiochus, and gave himself up to licentiousness [Polybius, 87; Justin, 30.4], and profaned the temple of God by entering the holy place [Grotius].

not be strengthened by it-He shall lose the power gained by his victory through his luxurious indolence.

Matthew Henry's Concise Commentary

11:1-30 The angel shows Daniel the succession of the Persian and Grecian empires. The kings of Egypt and Syria are noticed: Judea was between their dominions, and affected by their contests. From ver. 5-30, is generally considered to relate to the events which came to pass during the continuance of these governments; and from ver. 21, to relate to Antiochus Epiphanes, who was a cruel and violent persecutor of the Jews. See what decaying, perishing things worldly pomp and possessions are, and the power by which they are gotten. God, in his providence, sets up one, and pulls down another, as he pleases. This world is full of wars and fightings, which come from men's lusts. All changes and revolutions of states and kingdoms, and every event, are plainly and perfectly foreseen by God. No word of God shall fall to the ground; but what he has designed, what he has declared, shall infallibly come to pass. While the potsherds of the earth strive with each other, they prevail and are prevailed against, deceive and are deceived; but those who know God will trust in him, and he will enable them to stand their ground, bear their cross, and maintain their conflict.