Matthew 2:3

When Herod - heard these things, he was troubled - Herod's consternation was probably occasioned by the agreement of the account of the magi, with an opinion predominant throughout the east, and particularly in Judea, that some great personage would soon make his appearance, for the deliverance of Israel from their enemies; and would take upon himself universal empire.

Suetonius and Tacitus, two Roman historians, mention this. Their words are very remarkable: -

Percrebuerat Oriente toto, vetus et constans opinio, esse in fatis, ut eo tempore Judaea profecti rerum potirentur. Id de imperatare Romano, quantum eventu postea predictum patuit, Judaei ad se trahentes, rebellarunt.

Sueton. Vesp.

"An ancient and settled persuasion prevailed throughout the east, that the fates had decreed some to proceed from Judea, who should attain universal empire. This persuasion, which the event proved to respect the Roman emperor, the Jews applied to themselves, and therefore rebelled."

The words of Tacitus are nearly similar: -

Pluribus persuasio inerat, antiquis sacerdotum literis contineri, eo ipso tempore fore, ut valesceret Oriens, profectique Judaea rerum potirentur. Quae ambages Vespasianum ac Titum praedixerant.

"Many were persuaded, that it was contained in the ancient books of their priests, that at that very time the east should prevail: and that some should proceed from Judea and possess the dominion. It was Vespasian and Titus that these ambiguous prophecies predicted."

Histor. v.

Had heard these things - Had heard of their coming, and of the star, and of the design of their coming.

He was troubled - Herod had obtained the kingdom by great crimes, and by shedding much blood. He was therefore easily alarmed by any remarkable appearances; and the fact that this star appeared, and that it was regarded as proof that a King of the Jews was born, alarmed him. Besides, it was a common expectation that the Messiah was about to appear, and he feared that his reign was about to come to an end. He therefore began to inquire in what way he might secure his own safety and the permanency of his government.

All Jerusalem - The people of Jerusalem, and particularly the friends of Herod. There were many in Jerusalem to whom the coming of the Messiah would be a matter of joy; but all of Herod's friends would doubtless be alarmed at his coming.